diff --git a/.pi/skills/test-e32r40t-firmware/SKILL.md b/.pi/skills/test-e32r40t-firmware/SKILL.md
index 143c01d..bb129ad 100644
--- a/.pi/skills/test-e32r40t-firmware/SKILL.md
+++ b/.pi/skills/test-e32r40t-firmware/SKILL.md
@@ -75,8 +75,10 @@ entirely. Wait for the app's own ready log, then `sleep` a few seconds.
 `tap` always takes physical panel pixels (320x480 portrait), because the glass never rotates.
 
 Screens are laid out by `/lib/ui.lua`, so read tap targets off a `capture` rather than
-computing them. For the default launcher and settings styling (`pad = 12`, `gap = 8`, a
-title 8px tall, buttons 24px tall) rows land at y=28, 60 and 92.
+computing them. The status bar (`/lib/statusbar.lua`) takes the top 22 rows in every app,
+so for the default launcher and settings styling (`pad = 12`, `gap = 8`, a title 8px tall,
+buttons 24px tall) rows land at y=62, 96 and 128. Taps that land within the first few
+seconds after a ready log are missed, so `wait-idle 3` before the first one.
 
 Use `touch-hold` plus `capture` plus `touch-release` to photograph a pressed button:
 `on_press` fires on release, and the pressed style is only visible mid-gesture.
diff --git a/docs/lua-api-parity.md b/docs/lua-api-parity.md
index a05cb24..f140806 100644
--- a/docs/lua-api-parity.md
+++ b/docs/lua-api-parity.md
@@ -12,7 +12,7 @@ Compared against crosspoint-reader at `src/util/lua/LuaBindings*.cpp`.
 `fs.listDirs`, `fs.listFiles`, `fs.exists`, `fs.readFile`, `fs.writeFile`,
 `gui.width`, `gui.height`, `gui.fillRect`, `gui.drawRect`, `gui.drawLine`,
 `sys.millis`, `sys.delay`, `sys.exit`, `log.debug/info/error`, the whole `http` table,
-`app.setTickInterval`, `wifi.status`, `wifi.isConnected`, `wifi.localIP`, and the
+`sys.setTickInterval`, `wifi.status`, `wifi.isConnected`, `wifi.localIP`, and the
 `init()` / `draw()` / `on_tick()` callbacks. `init()` is required in both, so a
 misspelled entry point is an error rather than an app that quietly draws nothing.
 
@@ -27,7 +27,7 @@ strength a status screen wants. Its `state` vocabulary is a subset: crosspoint r
 | Area | crosspoint-reader | slate32 | Why |
 |---|---|---|---|
 | Input | `input.wasPressed(button)` and friends, 8 named buttons | `input.getTouch`, `getRawTouch`, `touched` | Different hardware. A touch panel has no button names and a button device has no coordinates. |
-| Drawing | `gui.drawText(font, x, y, text, color, style)`, `getTextWidth(font, text)` | `gui.drawText(text, x, y, color, bg)`, `textWidth(text)` | crosspoint ships several fonts; this firmware has one built-in font, and needs an opaque background colour because the panel is not e-ink. |
+| Drawing | `gui.drawText(font, x, y, text, color, style)`, `getTextWidth(font, text)` | `gui.drawText(text, x, y, color, bg)`, `textWidth(text)` | crosspoint ships several fonts; this firmware has one built-in font scaled by `gui.setTextSize(n)`, and needs an opaque background colour because the panel is not e-ink. |
 | Refresh | `gui.refresh(mode)`, `REFRESH_FULL/HALF/FAST` | none | An LCD has no waveform modes. |
 | Colour | `COLOR_*` constants, 4 grey levels | `gui.color(r, g, b)` returning RGB565 | 16-bit colour has too many values to enumerate. |
 | Shapes | `drawRoundedRect` + `fillRoundedRect` | one `gui.roundRect(...)` with gradient and border | Fill and border derive from a single distance field, so their edges cannot disagree. |
diff --git a/sdcard/apps/hello/main.lua b/sdcard/apps/hello/main.lua
index 470544b..7feba52 100644
--- a/sdcard/apps/hello/main.lua
+++ b/sdcard/apps/hello/main.lua
@@ -5,7 +5,7 @@ local seconds = 0
 local theme = ui.theme
 
 function init()
-  app.setTickInterval(1000)
+  sys.setTickInterval(1000)
   gui.clear(theme.bg)
   gui.drawText("hello from sd card", 10, 10, theme.fg, theme.bg)
   gui.drawText("touch the screen", 10, 30, theme.muted, theme.bg)
diff --git a/sdcard/apps/launcher/main.lua b/sdcard/apps/launcher/main.lua
index db99a84..9559b68 100644
--- a/sdcard/apps/launcher/main.lua
+++ b/sdcard/apps/launcher/main.lua
@@ -1,48 +1,51 @@
 local ui = require("ui")
 
+local PAD, GAP = 12, 8
+local CARD_SIZE = 2  -- text scale inside a card; the name is the whole card
+
 local screen
-local clock
 
--- Until the clock means something the placeholder holds its width; WiFi and SNTP run
--- in the background.
-local PLACEHOLDER = "--:--:--"
-
--- Rows are interactive containers rather than plain buttons, so each can carry a
--- name plus secondary text (and an icon later) while still being one tap target.
-local function appRow(name)
+local function card(name, side)
   return ui.button{
-    pad = {t = 8, r = 10, b = 8, l = 10},
-    align = "start",
+    w = side, h = side,
+    justify = "center",
     on_press = function() sys.launch("/apps/" .. name .. "/main.lua") end,
-    ui.text(name),
+    ui.label(name, {size = CARD_SIZE, fit = side - 16}),
   }
 end
 
 function init()
-  app.setTickInterval(500)  -- twice a second, so the seconds digit never visibly lags
-  -- Fixed width: drawText paints an opaque background only under its own glyphs, so a
-  -- shorter label would leave the tail of the previous one on screen.
-  clock = ui.text(PLACEHOLDER, {w = gui.textWidth(PLACEHOLDER), color = ui.theme.muted})
-  local header = ui.box{row = true, gap = 12, justify = "between", ui.text("slate32"), clock}
-  local items = {pad = 12, gap = 8, header}
-
-  local names = fs.listDirs("/apps")
+  local names = {}
+  for _, name in ipairs(fs.listDirs("/apps")) do
+    if name ~= "launcher" then names[#names + 1] = name end
+  end
   table.sort(names)
+
+  local side, cols = ui.cardSide(math.max(#names, 1), PAD, GAP)
+
+  -- Rows are filled before ui.box() sees them: the constructor moves a spec's array part
+  -- into its children, so anything appended afterwards is never laid out.
+  local rows = {}
   for _, name in ipairs(names) do
-    if name ~= "launcher" then items[#items + 1] = appRow(name) end
+    local row = rows[#rows]
+    if not row or #row >= cols then
+      row = {}
+      rows[#rows + 1] = row
+    end
+    row[#row + 1] = card(name, side)
   end
-  if #names <= 1 then
-    items[#items + 1] = ui.text("no apps in /apps", {color = ui.theme.muted})
+
+  local items = {pad = PAD, gap = GAP}
+  for _, row in ipairs(rows) do
+    row.row, row.gap = true, GAP
+    items[#items + 1] = ui.box(row)
   end
+  if #rows == 0 then items[#items + 1] = ui.text("no apps in /apps", {color = ui.theme.muted}) end
 
   screen = ui.screen(ui.box(items))
   log.info("launcher ready")
 end
 
-function on_tick()
-  clock:setText(sys.clockSynced() and os.date("%H:%M:%S") or PLACEHOLDER)
-end
-
 function draw() screen:draw() end
 function on_touch_down(x, y) screen:down(x, y) end
 function on_touch_up(x, y) screen:up(x, y) end
diff --git a/sdcard/apps/settings/main.lua b/sdcard/apps/settings/main.lua
index 980fcdd..6434748 100644
--- a/sdcard/apps/settings/main.lua
+++ b/sdcard/apps/settings/main.lua
@@ -1,6 +1,7 @@
 local ui = require("ui")
 
 local INSET = 30
+local MENU_PAD, MENU_GAP = 12, 8
 
 local screen, message, passwordLabel, passwordRow
 local mode = "menu"
@@ -53,6 +54,7 @@ local function finishCalibration()
   message = ok and "calibration saved" or "save failed"
   mode = "menu"
   gui.setRotation(sys.getRotation() / 90)
+  gui.fullscreen(false)
   buildMenu()
 end
 
@@ -61,6 +63,9 @@ function startCalibration()
   mode = "calibrate"
   samples, pending, armed = {}, nil, false
   gui.setRotation(0)
+  -- The targets sit at the physical corners and the samples are read in panel
+  -- coordinates, so the status bar cannot be allowed to shift the frame.
+  gui.fullscreen(true)
   drawTarget(1)
 end
 
@@ -94,40 +99,54 @@ local function zoneLabel()
   return current
 end
 
-local function cycleTimezone(button)
+local function cycleTimezone()
   local current = sys.getTimezone()
   local next_index = 1
   for index, zone in ipairs(zones) do
     if zone.tz == current then next_index = index % #zones + 1 end
   end
   local ok = sys.setTimezone(zones[next_index].tz)
-  if ok and not message then
-    button:setText("timezone: " .. zoneLabel())
-    return
-  end
   message = ok and "timezone saved" or "save failed"
   buildMenu()
 end
 
-local function statusLabel(status)
-  if status.state == "connected" then return "wifi: " .. status.ssid end
-  if status.ssid ~= "" then return "wifi: " .. status.state end
-  return "wifi: not configured"
+local function wifiValue(status)
+  if status.state == "connected" then return status.ssid end
+  if status.ssid ~= "" then return status.state end
+  return "not set"
+end
+
+local function card(side, title, value, on_press)
+  local spec = {
+    w = side, h = side, gap = 6,
+    justify = "center",
+    on_press = on_press,
+    ui.label(title, {size = 2, fit = side - 12}),
+  }
+  if value then spec[#spec + 1] = ui.label(value, {fit = side - 12}) end
+  return ui.button(spec)
 end
 
 function buildMenu()
   mode = "menu"
-  local items = {
-    pad = 12,
-    gap = 8,
-    ui.text("settings"),
-    ui.button{label = "calibrate touch", on_press = startCalibration},
-    ui.button{label = "rotation: " .. sys.getRotation() .. " deg", on_press = cycleRotation},
-    ui.button{label = statusLabel(wifi.status()), on_press = buildWifi},
-    ui.button{label = "theme: " .. ui.themeName, on_press = cycleTheme},
-    ui.button{label = "timezone: " .. zoneLabel(), on_press = cycleTimezone},
-    ui.button{label = "exit", on_press = sys.exit},
+  -- No title: the status bar already names the running app. The status line under the
+  -- grid is worth its rows, so the cards give it room rather than pushing it off screen.
+  local side, cols = ui.cardSide(6, MENU_PAD, MENU_GAP, message and 20 or 0)
+  local cards = {
+    card(side, "calibrate", "touch", startCalibration),
+    card(side, "rotation", sys.getRotation() .. " deg", cycleRotation),
+    card(side, "wifi", wifiValue(wifi.status()), buildWifi),
+    card(side, "theme", ui.themeName, cycleTheme),
+    card(side, "timezone", zoneLabel(), cycleTimezone),
+    card(side, "exit", nil, sys.exit),
   }
+
+  local items = {pad = MENU_PAD, gap = MENU_GAP}
+  for index = 1, #cards, cols do
+    local row = {row = true, gap = MENU_GAP}
+    for column = index, math.min(index + cols - 1, #cards) do row[#row + 1] = cards[column] end
+    items[#items + 1] = ui.box(row)
+  end
   if message then items[#items + 1] = ui.text(message) end
   themed(items)
 end
@@ -162,7 +181,7 @@ end
 function buildWifi()
   mode = "wifi"
   local status = wifi.status()
-  local items = {pad = 12, gap = 8, ui.text("wifi"), ui.text(statusLabel(status))}
+  local items = {pad = 12, gap = 8, ui.text("wifi"), ui.text("wifi: " .. wifiValue(status))}
   if status.state == "connected" then
     items[#items + 1] = ui.text("ip: " .. status.ip)
   end
@@ -332,7 +351,7 @@ function buildKeyboard()
 end
 
 function init()
-  app.setTickInterval(50)  -- calibration samples the raw panel between draws
+  sys.setTickInterval(50)  -- calibration samples the raw panel between draws
   buildMenu()
   log.info("settings ready")
 end
diff --git a/sdcard/lib/statusbar.lua b/sdcard/lib/statusbar.lua
new file mode 100644
index 0000000..3e7d721
--- /dev/null
+++ b/sdcard/lib/statusbar.lua
@@ -0,0 +1,46 @@
+-- The top bar, painted by the firmware once a second in every app. It draws in panel
+-- coordinates (the firmware drops the app viewport around the call), so gui.width()
+-- here is the whole screen.
+
+local ui = require("ui")
+
+local PAD = 6
+
+-- The firmware reads both: `height` is the strip it keeps apps out of, `interval` is how
+-- often it calls draw().
+local M = {height = 22, interval = 1000}
+local BAR_H = M.height
+
+local function clock()
+  return sys.clockSynced() and os.date("%H:%M") or "--:--"
+end
+
+-- Bars rather than glyphs: there is no icon font, and signal strength is a scale.
+local function drawSignal(x, y, color, muted)
+  local status = wifi.status()
+  local bars = 0
+  if status.state == "connected" then
+    bars = status.rssi >= -60 and 3 or status.rssi >= -75 and 2 or 1
+  end
+  for i = 1, 3 do
+    local h = i * 3
+    gui.fillRect(x + (i - 1) * 4, y + 9 - h, 3, h, i <= bars and color or muted)
+  end
+end
+
+function M.draw()
+  local theme = ui.theme
+  gui.setTextSize(1)  -- panel state: the app may have left it scaled up
+  local w = gui.width()
+  gui.fillRect(0, 0, w, BAR_H, theme.bg)
+  gui.fillRect(0, BAR_H - 1, w, 1, theme.muted)  -- a rule, so the bar reads as chrome
+
+  local textY = math.floor((BAR_H - 1 - gui.fontHeight()) / 2)
+  gui.drawText(sys.appName(), PAD, textY, theme.fg, theme.bg)
+
+  local time = clock()
+  gui.drawText(time, w - PAD - gui.textWidth(time), textY, theme.muted, theme.bg)
+  drawSignal(w - PAD - gui.textWidth(time) - 8 - 11, textY, theme.fg, theme.muted)
+end
+
+return M
diff --git a/sdcard/lib/ui.lua b/sdcard/lib/ui.lua
index 9abbf8f..0321dd5 100644
--- a/sdcard/lib/ui.lua
+++ b/sdcard/lib/ui.lua
@@ -315,13 +315,17 @@ function ui.spacer(spec)
   return component{w = spec.w, h = spec.h}
 end
 
+-- Text size is panel state, not node state, so every measure and paint sets it: a
+-- neighbour at another size would otherwise decide this node's metrics.
 local function measureText(self, available)
+  gui.setTextSize(self.size or 1)
   self.mw = resolve(self.w, available.w, "width") or gui.textWidth(self.label)
   self.mh = resolve(self.h, available.h, "height") or gui.fontHeight()
   return self.mw, self.mh
 end
 
 local function paintText(self)
+  gui.setTextSize(self.size or 1)
   gui.drawText(self.label, self.rect.x, self.rect.y, self.color, self.bg)
 end
 
@@ -341,6 +345,32 @@ function ui.text(label, spec)
   return node
 end
 
+-- Geometry for a grid of square cards: a wide frame takes another column, and the side
+-- shrinks until every row fits, because there is no scrolling and a card below the fold
+-- cannot be tapped. `reserve` is height the caller needs for anything under the grid.
+-- ponytail: enough cards make them unusably small; that is the point to add scrolling.
+function ui.cardSide(count, pad, gap, reserve)
+  local cols = gui.width() >= gui.height() and 3 or 2
+  local rows = math.ceil(count / cols)
+  local byWidth = (gui.width() - 2 * pad - (cols - 1) * gap) // cols
+  local byHeight = (gui.height() - 2 * pad - (reserve or 0) - (rows - 1) * gap) // rows
+  return math.min(byWidth, byHeight), cols
+end
+
+-- A text node sized to its own glyphs, so a centering parent has something to center: a
+-- plain ui.text takes the parent's full width and paints from its left edge. `fit` clips
+-- the label to a pixel budget, because the panel has one font and no wrapping.
+function ui.label(text, spec)
+  spec = spec or {}
+  gui.setTextSize(spec.size or 1)
+  if spec.fit and gui.textWidth(text) > spec.fit then
+    while #text > 1 and gui.textWidth(text .. "~") > spec.fit do text = text:sub(1, -2) end
+    text = text .. "~"
+  end
+  spec.w, spec.fit = gui.textWidth(text), nil
+  return ui.text(text, spec)
+end
+
 local function paintButton(self)
   local r = self.rect
   local gradient = self.pressed and self.press_gradient or (not self.pressed and self.gradient)
diff --git a/src/gfx/statusbar.h b/src/gfx/statusbar.h
new file mode 100644
index 0000000..f8a2377
--- /dev/null
+++ b/src/gfx/statusbar.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <TFT_eSPI.h>
+
+// Host-owned chrome across the top of the panel. Apps draw inside a viewport below it,
+// so nothing an app paints can reach the bar and every app's gui.height() shrinks by the
+// bar without the app knowing it exists. Both the painting and the height live in
+// /lib/statusbar.lua; the firmware only owns the clipping.
+namespace statusbar {
+
+constexpr int16_t DEFAULT_H = 22;  // when /lib/statusbar.lua declares no height
+
+// resetViewport() first: width()/height() report the *viewport* once one is set, so
+// re-applying over an existing viewport would shrink the app area again every time.
+// setRotation() leaves the old viewport metrics behind, so every rotation needs this too.
+inline void apply(TFT_eSPI& tft, int16_t barHeight) {
+  tft.resetViewport();
+  if (barHeight > 0) tft.setViewport(0, barHeight, tft.width(), tft.height() - barHeight, true);
+}
+
+}  // namespace statusbar
diff --git a/src/lua/bindings/gui.cpp b/src/lua/bindings/gui.cpp
index ff5ac76..a056eac 100644
--- a/src/lua/bindings/gui.cpp
+++ b/src/lua/bindings/gui.cpp
@@ -96,6 +96,13 @@ static int l_gui_fontHeight(lua_State* L) {
   return 1;
 }
 
+// Integer multiples of the one built-in font, which is all the driver offers. fontHeight()
+// and textWidth() follow it, so layout keeps working at any size.
+static int l_gui_setTextSize(lua_State* L) {
+  app(L)->tft.setTextSize(constrain(luaL_checkinteger(L, 1), 1, 8));
+  return 0;
+}
+
 static int l_gui_textWidth(lua_State* L) {
   lua_pushinteger(L, app(L)->tft.textWidth(luaL_checkstring(L, 1)));
   return 1;
@@ -113,6 +120,14 @@ static int l_gui_drawText(lua_State* L) {
 // Only the current frame; sys.setRotation() is the persisted one.
 static int l_gui_setRotation(lua_State* L) {
   app(L)->tft.setRotation(luaL_checkinteger(L, 1));
+  app(L)->applyViewport();
+  return 0;
+}
+
+// Escape hatch for an app that must reach the physical edges, like touch calibration:
+// the status bar and the viewport that keeps apps out of it both go away.
+static int l_gui_fullscreen(lua_State* L) {
+  app(L)->setFullscreen(lua_toboolean(L, 1));
   return 0;
 }
 
@@ -128,6 +143,9 @@ void registerGui(lua_State* L) {
       // --- Panel width in pixels, for the current rotation.
       // @return integer
       {"width", l_gui_width},
+      // --- Hands the app the whole panel, hiding the status bar, until it is turned off.
+      // @param on boolean
+      {"fullscreen", l_gui_fullscreen},
       // --- Panel height in pixels, for the current rotation.
       // @return integer
       {"height", l_gui_height},
@@ -181,7 +199,10 @@ void registerGui(lua_State* L) {
       // @param bottom integer|nil Bottom of the gradient, defaults to top.
       // @param border integer|nil Border color; omitted draws no border.
       {"roundRect", l_gui_roundRect},
-      // --- Height of the current font in pixels.
+      // --- Scales the built-in font by a whole number, for this app only.
+      // @param size integer 1 to 8.
+      {"setTextSize", l_gui_setTextSize},
+      // --- Height of the current font in pixels, at the current text size.
       // @return integer
       {"fontHeight", l_gui_fontHeight},
       // --- Width the given text would occupy in pixels.
diff --git a/src/lua/bindings/input.cpp b/src/lua/bindings/input.cpp
index 279eccc..db8757e 100644
--- a/src/lua/bindings/input.cpp
+++ b/src/lua/bindings/input.cpp
@@ -12,7 +12,7 @@ static int l_input_getTouch(lua_State* L) {
   }
   TS_Point point = owner->touch.getPoint();
   int16_t x, y;
-  LuaApp::mapTouch(owner->tft, point, x, y);
+  owner->mapTouch(point, x, y);
   lua_pushinteger(L, x);
   lua_pushinteger(L, y);
   return 2;
diff --git a/src/lua/bindings/sys.cpp b/src/lua/bindings/sys.cpp
index 99812ad..1ed8de2 100644
--- a/src/lua/bindings/sys.cpp
+++ b/src/lua/bindings/sys.cpp
@@ -15,6 +15,11 @@ static int l_sys_exit(lua_State* L) {
   return 0;
 }
 
+static int l_sys_appName(lua_State* L) {
+  lua_pushstring(L, app(L)->name().c_str());
+  return 1;
+}
+
 static int l_sys_launch(lua_State* L) {
   app(L)->requestLaunch(luaL_checkstring(L, 1));
   app(L)->requestExit();
@@ -33,6 +38,7 @@ static int l_sys_setRotation(lua_State* L) {
     return 1;
   }
   app(L)->tft.setRotation(settings.rotationIndex());
+  app(L)->applyViewport();
   lua_pushboolean(L, settings.save());
   return 1;
 }
@@ -98,7 +104,7 @@ static int logAt(lua_State* L, const char* level) {
 
 // Rejected rather than ignored when on_tick is absent: the chunk body has already run
 // by the time init() calls this, so a missing callback is a typo, not a race.
-static int l_app_setTickInterval(lua_State* L) {
+static int l_sys_setTickInterval(lua_State* L) {
   lua_Integer requested = luaL_checkinteger(L, 1);
   if (requested <= 0) {
     app(L)->setTickInterval(0);
@@ -107,7 +113,7 @@ static int l_app_setTickInterval(lua_State* L) {
   lua_getglobal(L, "on_tick");
   bool hasTick = lua_isfunction(L, -1);
   lua_pop(L, 1);
-  if (!hasTick) return luaL_error(L, "app.setTickInterval() requires on_tick()");
+  if (!hasTick) return luaL_error(L, "sys.setTickInterval() requires on_tick()");
 
   uint32_t interval = requested < (lua_Integer)LuaApp::MIN_TICK_MS ? LuaApp::MIN_TICK_MS
                       : requested > (lua_Integer)LuaApp::MAX_TICK_MS ? LuaApp::MAX_TICK_MS
@@ -137,6 +143,12 @@ void registerSys(lua_State* L) {
       {"delay", l_sys_delay},
       // --- Ends this app and returns to the launcher.
       {"exit", l_sys_exit},
+      // --- Directory name of the running app, for example "settings".
+      // @return string
+      {"appName", l_sys_appName},
+      // --- Sets how often on_tick() runs. Errors when on_tick is not defined.
+      // @param intervalMs integer 0 stops ticking; anything else is clamped to 33..3600000.
+      {"setTickInterval", l_sys_setTickInterval},
       // --- Ends this app and starts another one.
       // @param path string Absolute path to the app's main.lua.
       {"launch", l_sys_launch},
@@ -175,15 +187,7 @@ void registerSys(lua_State* L) {
   luaL_newlib(L, lib);
   lua_setglobal(L, "sys");
 
-  // These two are too small to deserve their own translation units.
-  static const luaL_Reg appLib[] = {
-      // --- Sets how often on_tick() runs. Errors when on_tick is not defined.
-      // @param intervalMs integer 0 stops ticking; anything else is clamped to 33..3600000.
-      {"setTickInterval", l_app_setTickInterval},
-      {nullptr, nullptr}};
-  luaL_newlib(L, appLib);
-  lua_setglobal(L, "app");
-
+  // Too small to deserve its own translation unit.
   static const luaL_Reg logLib[] = {
       // --- Writes a debug line to the serial log.
       // @param message string
diff --git a/src/lua/lua_app.cpp b/src/lua/lua_app.cpp
index baa6359..f2bdb03 100644
--- a/src/lua/lua_app.cpp
+++ b/src/lua/lua_app.cpp
@@ -5,6 +5,7 @@
 
 #include <algorithm>
 
+#include "../gfx/statusbar.h"
 #include "../settings.h"
 #include "bindings.h"
 
@@ -19,7 +20,7 @@ LuaApp* app(lua_State* L) { return *static_cast<LuaApp**>(lua_getextraspace(L));
 
 void bindApp(lua_State* L, LuaApp* owner) { *static_cast<LuaApp**>(lua_getextraspace(L)) = owner; }
 
-void LuaApp::mapTouch(TFT_eSPI& tft, const TS_Point& p, int16_t& x, int16_t& y) {
+void LuaApp::mapTouch(const TS_Point& p, int16_t& x, int16_t& y) const {
   int16_t nx = constrain(map(p.y, settings.touchX0, settings.touchX1, 0, PANEL_W), 0, PANEL_W - 1);
   int16_t ny = constrain(map(p.x, settings.touchY0, settings.touchY1, 0, PANEL_H), 0, PANEL_H - 1);
   switch (tft.getRotation() & 3) {
@@ -40,6 +41,17 @@ void LuaApp::mapTouch(TFT_eSPI& tft, const TS_Point& p, int16_t& x, int16_t& y)
       y = ny;
       break;
   }
+  // App space starts below the bar, matching the viewport apps draw into. A tap on the
+  // bar itself lands at a negative y, which loop() drops.
+  y -= barInset();
+}
+
+void LuaApp::applyViewport() { statusbar::apply(tft, barInset()); }
+
+void LuaApp::setFullscreen(bool on) {
+  fullscreen = on;
+  applyViewport();
+  nextBarMs = 0;  // leaving fullscreen left the bar's rows painted by the app
 }
 
 LuaApp::LuaApp(TFT_eSPI& tft, XPT2046_Touchscreen& touch) : tft(tft), touch(touch) {}
@@ -105,7 +117,14 @@ bool LuaApp::load(const char* path) {
 
   String appDir = path;
   int slash = appDir.lastIndexOf('/');
-  installLoader(slash > 0 ? appDir.substring(0, slash).c_str() : "/");
+  appDir = slash > 0 ? appDir.substring(0, slash) : String("/");
+  installLoader(appDir.c_str());
+  appName = appDir.substring(appDir.lastIndexOf('/') + 1);
+
+  // Before the chunk runs: the bar's height sets the viewport, and an app measuring
+  // gui.height() at the top of init() has to see the area it actually owns.
+  loadStatusBar();
+  applyViewport();
 
   if (loadScript(state, path) != LUA_OK) {
     fail(lua_tostring(state, -1));
@@ -123,6 +142,50 @@ bool LuaApp::load(const char* path) {
   return running();
 }
 
+// Reads an optional positive integer field off the bar module on the stack top.
+static lua_Integer barField(lua_State* L, const char* key, lua_Integer fallback) {
+  lua_getfield(L, -1, key);
+  lua_Integer value = lua_isinteger(L, -1) ? lua_tointeger(L, -1) : fallback;
+  lua_pop(L, 1);
+  return value > 0 ? value : fallback;
+}
+
+// The bar is a Lua module like any other, loaded per app because the state is too. Its
+// own table owns the geometry and the repaint rate: sys.setTickInterval() belongs to the
+// app, and there is only one of those per state.
+void LuaApp::loadStatusBar() {
+  barBroken = false;
+  barHeight = statusbar::DEFAULT_H;
+  barIntervalMs = BAR_INTERVAL_MS;
+  lua_getglobal(state, "require");
+  lua_pushstring(state, "statusbar");
+  if (lua_pcall(state, 1, 1, 0) != LUA_OK || !lua_istable(state, -1)) {
+    Serial.printf("[statusbar] unavailable: %s\n", luaL_tolstring(state, -1, nullptr));
+    barBroken = true;
+    lua_pop(state, 2);
+    return;
+  }
+  barHeight = barField(state, "height", statusbar::DEFAULT_H);
+  barIntervalMs = std::max((lua_Integer)MIN_TICK_MS, barField(state, "interval", BAR_INTERVAL_MS));
+  lua_setglobal(state, "__statusbar");
+  nextBarMs = 0;
+}
+
+// Errors here are logged and disable the bar rather than killing the app: chrome that
+// fails should not take the running program with it.
+void LuaApp::drawStatusBar() {
+  lua_getglobal(state, "__statusbar");
+  lua_getfield(state, -1, "draw");
+  lua_remove(state, -2);
+  tft.resetViewport();  // the bar paints in panel coordinates, the app does not
+  if (lua_pcall(state, 0, 0, 0) != LUA_OK) {
+    Serial.printf("[statusbar] %s\n", luaL_tolstring(state, -1, nullptr));
+    lua_pop(state, 2);
+    barBroken = true;
+  }
+  applyViewport();
+}
+
 void LuaApp::setTickInterval(uint32_t intervalMs) {
   tickIntervalMs = intervalMs;
   nextTickMs = millis() + intervalMs;
@@ -165,7 +228,8 @@ void LuaApp::loop() {
   bool touched = touch.touched();
   if (touched) {
     TS_Point p = touch.getPoint();
-    mapTouch(tft, p, lastX, lastY);
+    mapTouch(p, lastX, lastY);
+    if (lastY < 0) touched = false;  // the bar is the host's, and it takes no input yet
   }
   if (touched && !lastTouched) {
     fireTouch("on_touch_down", lastX, lastY);
@@ -191,5 +255,11 @@ void LuaApp::loop() {
     nextDrawMs = now + DRAW_INTERVAL_MS;
     lua_getglobal(state, "draw");
     callGlobal("draw");
+    if (!running()) return;
+  }
+
+  if (barInset() > 0 && now >= nextBarMs) {
+    nextBarMs = now + barIntervalMs;
+    drawStatusBar();
   }
 }
diff --git a/src/lua/lua_app.h b/src/lua/lua_app.h
index ce2d64f..b6a990f 100644
--- a/src/lua/lua_app.h
+++ b/src/lua/lua_app.h
@@ -18,6 +18,17 @@ class LuaApp {
   bool load(const char* path);
   void loop();
 
+  // Directory name of the running app ("launcher"), for the status bar.
+  const String& name() const { return appName; }
+
+  // Lets an app own the whole panel: no viewport, no status bar. The touch calibration
+  // needs the physical edges; almost nothing else should.
+  void setFullscreen(bool on);
+
+  // Re-clips the app out of the status bar. Needed after every setRotation(), which
+  // leaves the previous viewport metrics behind.
+  void applyViewport();
+
   // Set by sys.launch(); the host loop reads it once the app has torn down.
   void requestLaunch(const char* path);
   String takePendingLaunch();
@@ -28,7 +39,7 @@ class LuaApp {
   // can leave the message on screen long enough to read.
   bool takeFailure();
 
-  // Set from Lua by app.setTickInterval(); 0 stops the ticks.
+  // Set from Lua by sys.setTickInterval(); 0 stops the ticks.
   void setTickInterval(uint32_t intervalMs);
 
   static constexpr uint32_t MIN_TICK_MS = 33;        // no point ticking faster than a draw
@@ -39,7 +50,8 @@ class LuaApp {
   static constexpr int16_t PANEL_W = 320;
   static constexpr int16_t PANEL_H = 480;
 
-  static void mapTouch(TFT_eSPI& tft, const TS_Point& p, int16_t& x, int16_t& y);
+  // App coordinates, so the status bar's rows are subtracted unless the app owns the panel.
+  void mapTouch(const TS_Point& p, int16_t& x, int16_t& y) const;
 
   static constexpr size_t READ_CAP = 64 * 1024;
   static constexpr int MAX_SPAN = 480;  // longest panel edge, so one row buffer covers any shape
@@ -51,6 +63,14 @@ class LuaApp {
   String pendingLaunch;
   bool lastTouched = false;
   bool ignoreRelease = false;
+  bool fullscreen = false;
+  String appName;
+  // One strike: a bar that failed once fails identically every second, and the serial
+  // log is the only place anyone would see it.
+  bool barBroken = false;
+  int16_t barHeight = 0;
+  uint32_t nextBarMs = 0;
+  uint32_t barIntervalMs = 0;
   // The controller reports no position once the finger lifts, so on_touch_up and the
   // tap alias replay the last point seen while it was down.
   int16_t lastX = 0, lastY = 0;
@@ -58,11 +78,19 @@ class LuaApp {
   void closeState();
   void installLoader(const char* appDir);
   void fireTouch(const char* name, int16_t x, int16_t y);
+  void loadStatusBar();
+  void drawStatusBar();
   uint32_t tickIntervalMs = 0;
   uint32_t nextTickMs = 0;
   uint32_t nextDrawMs = 0;
 
   static constexpr uint32_t DRAW_INTERVAL_MS = 33;
+  // Default only: /lib/statusbar.lua overrides it with an `interval` field.
+  static constexpr uint32_t BAR_INTERVAL_MS = 1000;
+
+  // Zero whenever the app owns the panel, so one accessor answers both the viewport
+  // and the touch offset.
+  int16_t barInset() const { return (fullscreen || barBroken) ? 0 : barHeight; }
 
   void registerBindings();
   bool callGlobal(const char* name, int nargs = 0);
diff --git a/src/main.cpp b/src/main.cpp
index f8329e4..7f634c7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4,6 +4,7 @@
 #include <WiFi.h>
 #include <XPT2046_Touchscreen.h>
 
+#include "gfx/statusbar.h"
 #include "lua/lua_app.h"
 #include "net.h"
 #include "settings.h"
@@ -35,6 +36,7 @@ String nextApp;
 // Last resort only: the UI lives in Lua, so this exists purely to explain why
 // nothing else could run.
 void fallbackScreen(const char* message) {
+  tft.resetViewport();  // no app, no status bar: this message owns the panel
   tft.setRotation(0);
   tft.fillScreen(TFT_WHITE);
   tft.setTextColor(TFT_RED, TFT_WHITE);
@@ -46,7 +48,9 @@ void fallbackScreen(const char* message) {
 }
 
 void startApp(const String& path) {
+  // Full panel until the app's own status bar module reports its height in load().
   tft.setRotation(settings.rotationIndex());  // apps may have rotated the frame
+  statusbar::apply(tft, 0);
   Serial.printf("launching %s\n", path.c_str());
   if (app.load(path.c_str())) return;
   if (path == LAUNCHER) fallbackScreen("launcher failed to start");
diff --git a/stubs/slate32.lua b/stubs/slate32.lua
index c96ef5f..0a27af0 100644
--- a/stubs/slate32.lua
+++ b/stubs/slate32.lua
@@ -4,13 +4,6 @@
 -- Point your editor's Lua language server at this file to get completion for the
 -- firmware API inside sdcard/apps and sdcard/lib.
 
----@class applib
-app = {}
-
---- Sets how often on_tick() runs. Errors when on_tick is not defined.
----@param intervalMs integer 0 stops ticking; anything else is clamped to 33..3600000.
-function app.setTickInterval(intervalMs) end
-
 ---@class fslib
 fs = {}
 
@@ -47,6 +40,10 @@ gui = {}
 ---@return integer
 function gui.width() end
 
+--- Hands the app the whole panel, hiding the status bar, until it is turned off.
+---@param on boolean
+function gui.fullscreen(on) end
+
 --- Panel height in pixels, for the current rotation.
 ---@return integer
 function gui.height() end
@@ -108,7 +105,11 @@ function gui.drawText(text, x, y, color, bg) end
 ---@param border integer? Border color; omitted draws no border.
 function gui.roundRect(x, y, w, h, radius, bg, top, bottom, border) end
 
---- Height of the current font in pixels.
+--- Scales the built-in font by a whole number, for this app only.
+---@param size integer 1 to 8.
+function gui.setTextSize(size) end
+
+--- Height of the current font in pixels, at the current text size.
 ---@return integer
 function gui.fontHeight() end
 
@@ -227,6 +228,14 @@ function sys.delay(ms) end
 --- Ends this app and returns to the launcher.
 function sys.exit() end
 
+--- Directory name of the running app, for example "settings".
+---@return string
+function sys.appName() end
+
+--- Sets how often on_tick() runs. Errors when on_tick is not defined.
+---@param intervalMs integer 0 stops ticking; anything else is clamped to 33..3600000.
+function sys.setTickInterval(intervalMs) end
+
 --- Ends this app and starts another one.
 ---@param path string Absolute path to the app's main.lua.
 function sys.launch(path) end
diff --git a/test/fake_device.lua b/test/fake_device.lua
index aae05bf..1ebec47 100644
--- a/test/fake_device.lua
+++ b/test/fake_device.lua
@@ -14,6 +14,9 @@ local device = {
   theme = "light",
   clockSynced = false,
   tickInterval = 0,
+  appName = "test",
+  textSize = 1,
+  fullscreen = false,
   timezone = "UTC0",
   raw = nil,          -- pending raw touch reading, {x, y} or nil
   networks = {},      -- what wifi.scan() returns
@@ -47,14 +50,21 @@ function device.install()
     drawText = function(label, x, y)
       device.painted[#device.painted + 1] = {label = label, x = x, y = y}
     end,
-    fontHeight = function() return device.fontHeight end,
-    textWidth = function(text) return #text * device.charWidth end,
+    setTextSize = function(size) device.textSize = size end,
+    fontHeight = function() return device.fontHeight * device.textSize end,
+    textWidth = function(text) return #text * device.charWidth * device.textSize end,
     setRotation = function() end,
+    fullscreen = function(on) device.fullscreen = on and true or false end,
   }
 
   sys = {
     millis = function() return device.now end,
     exit = function() device.exited = true end,
+    appName = function() return device.appName end,
+    setTickInterval = function(ms)
+      assert(ms == 0 or on_tick, "setTickInterval without on_tick")
+      device.tickInterval = ms
+    end,
     launch = function(path) device.launched = path end,
     getRotation = function() return device.rotation end,
     setRotation = function(degrees)
@@ -100,13 +110,6 @@ function device.install()
     forget = function() device.connected = nil return saved() end,
   }
 
-  app = {
-    setTickInterval = function(ms)
-      assert(ms == 0 or on_tick, "setTickInterval without on_tick")
-      device.tickInterval = ms
-    end,
-  }
-
   log = {debug = function() end, info = function() end, error = function() end}
 
   return device
diff --git a/test/settings_calibration.lua b/test/settings_calibration.lua
index dcf213e..f0fa2a7 100644
--- a/test/settings_calibration.lua
+++ b/test/settings_calibration.lua
@@ -20,7 +20,9 @@ local function tapRow(prefix)
   local target
   for _, item in ipairs(device.painted) do
     targets[item.label] = item
-    if item.label:sub(1, #prefix) == prefix then target = item end
+    -- First match wins: the status line at the bottom repeats a row's words back
+    -- ("timezone saved"), and tapping that hits nothing.
+    if not target and item.label:sub(1, #prefix) == prefix then target = item end
   end
   if not target then
     for label, item in pairs(targets) do
@@ -50,20 +52,18 @@ local s4 = {x = 3800 - raw(w - inset, w) + 200, y = s2.y}
 local fx0, _, fx1 = computeCalibration(s3, s4, w, h, inset)
 assert(fx0 > fx1, "flipped axis should descend")
 
--- Timezone cycles through the picker list and redraws only its button.
+-- Timezone cycles through the picker list.
 local zones = require("timezones")
 init()
-tapRow("timezone:")
+tapRow("timezone")
 assert(sys.getTimezone() == zones[2].tz, "timezone " .. sys.getTimezone())
-tapRow("timezone:")
-assert(#device.painted == 1 and device.painted[1].label == "timezone: " .. zones[2].name,
-       "timezone change repainted the settings list")
+tapRow("timezone")
 assert(sys.getTimezone() == zones[3].tz, "timezone " .. sys.getTimezone())
 
 -- Rotation cycles through the four quarter turns and wraps back to 0.
 init()
 for _, expected in ipairs({90, 180, 270, 0}) do
-  tapRow("rotation:")
+  tapRow("rotation")
   assert(sys.getRotation() == expected, "rotation " .. sys.getRotation())
 end
 
@@ -86,7 +86,7 @@ assert(math.abs(saved[1] - 200) <= 1, "saved x0 " .. saved[1])
 -- Open networks connect directly from scan results.
 init()
 device.networks = {{ssid = "qemu", rssi = -25, secure = false}}
-tapRow("wifi:")
+tapRow("wifi")
 tapRow("scan networks")
 on_tick()
 tapRow("qemu")
@@ -96,7 +96,7 @@ assert(device.connected[1] == "qemu" and device.connected[2] == "", "open wifi c
 -- Secure networks route through the keyboard and preserve typed punctuation.
 init()
 device.networks = {{ssid = "secure", rssi = -40, secure = true}}
-tapRow("wifi:")
+tapRow("wifi")
 tapRow("scan networks")
 on_tick()
 tapRow("secure")