diff --git a/README.md b/README.md
index b149155..77c2645 100644
--- a/README.md
+++ b/README.md
@@ -32,3 +32,31 @@ p, err := store.Decrypt("myPass")
 
 Also included is a simple GUI front-end using [Gio](https://gioui.org)
 that works on MacOS and Android. See `cmd/passgo-gui`.
+
+## Building the Android APK
+
+Use `scripts/build.sh` — do not build by hand:
+
+```sh
+./scripts/build.sh phone          # build + install on the phone
+./scripts/build.sh phone --no-install
+./scripts/build.sh emu            # emulator build (amd64)
+```
+
+It outputs `cmd/passgo-gui/passgo-gui.apk` (APKs are git-ignored and
+regenerated by the script). The script, in order:
+
+1. `gogio -target android -targetsdk 34` (from `~/go/bin`; packages the
+   Go code plus the `*.jar` JNI classes found in `cmd/passgo-gui/`),
+2. apktool decode → inject `MANAGE_EXTERNAL_STORAGE` into the manifest
+   (gogio's hardcoded permission table lacks it, and without it the
+   system "All files access" toggle is grayed out on Android 11+) →
+   apktool rebuild,
+3. sign with the debug keystore (`~/.android/debug.keystore`),
+4. `adb install -r`.
+
+Prereqs: JDK, Go + gogio, Android SDK at `~/android-sdk`
+(platform-tools + build-tools 35.0.0). apktool v3.0.3 is auto-downloaded
+to `~/android-sdk/tools/apktool.jar` if missing. The script checks each
+prereq and says what is missing. The phone is reached via adb over the
+WireGuard address (see the global AGENTS.md).
diff --git a/cmd/passgo-gui/main.go b/cmd/passgo-gui/main.go
index 1a1a7d3..1498613 100644
--- a/cmd/passgo-gui/main.go
+++ b/cmd/passgo-gui/main.go
@@ -10,6 +10,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"gioui.org/app"
@@ -99,7 +100,7 @@ func main() {
 	}
 
 	reload = make(chan struct{})
-	updated = make(chan struct{})
+	updated = make(chan struct{}, 1)
 	chdir = make(chan struct{})
 	passch = make(chan []byte)
 
@@ -127,6 +128,7 @@ var (
 	chdir      chan struct{}
 	passch     chan []byte
 	th         *material.Theme
+	win        atomic.Pointer[app.Window]
 )
 
 func Updater() {
@@ -140,7 +142,20 @@ func Updater() {
 		mux.Lock()
 		l = ltmp
 		mux.Unlock()
-		updated <- struct{}{}
+		// Non-blocking: if a refresh is already pending it will pick up
+		// the latest list, so dropping the duplicate is fine.
+		select {
+		case updated <- struct{}{}:
+		default:
+		}
+		// Wake the window: the event loop blocks in w.Event(), which only
+		// returns when the window is invalidated or the user interacts
+		// with it. Without this, a list refresh signalled while the loop
+		// is blocked (e.g. the initial load on startup) would not be
+		// drawn until the next tap.
+		if w := win.Load(); w != nil {
+			w.Invalidate()
+		}
 	}
 	update()
 
@@ -212,6 +227,7 @@ func eventLoop() {
 	w.Option(
 		app.Size(unit.Dp(250), unit.Dp(500)),
 		app.Title("passgo"))
+	win.Store(w)
 
 	var margincs layout.Constraints
 
@@ -401,18 +417,49 @@ func eventLoop() {
 	noidLabel := material.Label(th, unit.Sp(fontSize), noidLabelText)
 	idLabel := material.Label(th, unit.Sp(fontSize), "Select ID")
 
+	// timing variables used for the "copied to clipboard" animation
+	// (seconds relative to overlayStart)
+	fade1a, fade1b := 1.5, 2.0
+	start2 := float64(Config.ClearDelay)
+	fade2a, end := start2+1.5, start2+2.0
+
 	anim := &time.Ticker{}
+	var animDone chan struct{}
 	animating := false
 	animOn := func() {
 		log(Info, "animOn()")
 		anim = time.NewTicker(time.Second / 90)
 		animating = true
 		w.Invalidate()
+		// The event loop blocks in w.Event() between frames, so ticks it
+		// misses never trigger a redraw and the fade would freeze. Wake
+		// the window on each tick, but only while a fade is actually
+		// visible.
+		t := anim
+		animDone = make(chan struct{})
+		d := animDone
+		go func() {
+			for {
+				select {
+				case <-t.C:
+					x := time.Since(overlayStart).Seconds()
+					if (x >= fade1a && x < fade1b) || (x > fade2a && x < end) {
+						w.Invalidate()
+					}
+				case <-d:
+					return
+				}
+			}
+		}()
 	}
 	animOff := func() {
 		log(Info, "animOff()")
 		anim.Stop()
 		animating = false
+		if animDone != nil { // stops the wake-up goroutine started by animOn
+			close(animDone)
+			animDone = nil
+		}
 	}
 
 	var listPage, idPage, insertPage, confirmPage, confPage, promptPage, page func(C) D
@@ -427,11 +474,6 @@ func eventLoop() {
 
 	lpf1 := &layout.Flex{Axis: layout.Horizontal}
 	listPage = func(gtx C) D {
-		// timing variables used for animation
-		fade1a, fade1b := 1.5, 2.0
-		start2 := float64(Config.ClearDelay)
-		fade2a, end := start2+1.5, start2+2.0
-
 		c2 := layout.Rigid(func(gtx C) D {
 			c21 := layout.Flexed(1, func(gtx C) D {
 				return material.Editor(th, FilterEd, "filter").Layout(gtx)
diff --git a/scripts/build.sh b/scripts/build.sh
new file mode 100755
index 0000000..4684210
--- /dev/null
+++ b/scripts/build.sh
@@ -0,0 +1,99 @@
+#!/usr/bin/env bash
+# Build (and optionally install) the passgo-gui Android APK.
+#
+# Usage:
+#   ./scripts/build.sh [phone|emu]              # build + install (default: phone)
+#   ./scripts/build.sh phone --no-install       # build only
+#
+# Output: cmd/passgo-gui/passgo-gui.apk
+#
+# Prereqs on this workstation:
+#   - JDK (java on PATH)
+#   - Go + gogio (~/go/bin)
+#   - Android SDK at ~/android-sdk (platform-tools, build-tools 35.0.0)
+#   - debug keystore at ~/.android/debug.keystore
+# apktool is not a prerequisite: if it is missing, the script downloads
+# v3.0.3 to the stable location ~/android-sdk/tools/apktool.jar.
+#
+# Why the apktool detour: gogio's manifest permissions come from a hardcoded
+# table (only the legacy READ/WRITE_EXTERNAL_STORAGE). On Android 11+ the
+# "All files access" settings toggle is grayed out unless the app declares
+# MANAGE_EXTERNAL_STORAGE, which Permissions.java opens at startup. So we
+# decode the gogio APK, inject the permission, rebuild, and re-sign with
+# the debug key.
+set -euo pipefail
+
+REPO=$(cd "$(dirname "$0")/.." && pwd)
+export ANDROID_HOME=${ANDROID_HOME:-$HOME/android-sdk}
+export PATH=$PATH:$ANDROID_HOME/platform-tools:$ANDROID_HOME/build-tools/35.0.0:$HOME/go/bin
+
+MODE=${1:-phone}
+INSTALL=1
+[ "${2:-}" = "--no-install" ] && INSTALL=0
+case "$MODE" in
+    phone) ARCH="arm64,arm";;
+    emu)   ARCH="amd64";;
+    *) echo "usage: $0 [phone|emu] [--no-install]" >&2; exit 1;;
+esac
+
+die() { echo "ERROR: $*" >&2; exit 1; }
+
+command -v java      >/dev/null 2>&1 || die "java not found"
+command -v gogio     >/dev/null 2>&1 || die "gogio not found (need ~/go/bin)"
+command -v apksigner >/dev/null 2>&1 || die "apksigner not found (need $ANDROID_HOME/build-tools/35.0.0)"
+command -v adb       >/dev/null 2>&1 || die "adb not found (need $ANDROID_HOME/platform-tools)"
+[ -f "$HOME/.android/debug.keystore" ] || die "debug keystore missing: $HOME/.android/debug.keystore"
+
+# apktool: auto-download to a stable location if missing.
+APKTOOL="$ANDROID_HOME/tools/apktool.jar"
+if [ ! -f "$APKTOOL" ]; then
+	echo "=== apktool missing; downloading v3.0.3 to $APKTOOL ==="
+	mkdir -p "$ANDROID_HOME/tools"
+	curl -fsSL -o "$APKTOOL" \
+		https://github.com/iBotPeaches/Apktool/releases/download/v3.0.3/apktool_3.0.3.jar \
+		|| die "apktool download failed"
+fi
+
+WORK=$(mktemp -d)
+trap 'rm -rf "$WORK"' EXIT
+
+echo "=== gogio (Go -> APK) ==="
+# targetSdk 34: targeting 35 makes Android 15 force edge-to-edge, which the
+# app does not handle.
+(cd "$REPO/cmd/passgo-gui" && gogio -target android -targetsdk 34 -arch "$ARCH" -o "$WORK/passgo-raw.apk" .)
+[ -f "$WORK/passgo-raw.apk" ] || die "gogio did not produce an APK"
+
+echo "=== apktool decode + inject MANAGE_EXTERNAL_STORAGE ==="
+java -jar "$APKTOOL" d "$WORK/passgo-raw.apk" -o "$WORK/decoded" -f >/dev/null
+python3 - "$WORK/decoded/AndroidManifest.xml" << 'PYEOF'
+import sys, pathlib
+p = pathlib.Path(sys.argv[1])
+t = p.read_text()
+perm = '<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>'
+if perm not in t:
+    t = t.replace("    <application", "    " + perm + "\n    <application", 1)
+    if perm not in t:
+        sys.exit("ERROR: failed to inject MANAGE_EXTERNAL_STORAGE")
+p.write_text(t)
+print("manifest: MANAGE_EXTERNAL_STORAGE present")
+PYEOF
+
+echo "=== apktool rebuild ==="
+java -jar "$APKTOOL" b "$WORK/decoded" -o "$WORK/passgo-unsigned.apk" >/dev/null
+
+echo "=== sign ==="
+apksigner sign \
+	--ks "$HOME/.android/debug.keystore" --ks-pass pass:android \
+	--key-pass pass:android --ks-key-alias androiddebugkey \
+	--out "$REPO/cmd/passgo-gui/passgo-gui.apk" "$WORK/passgo-unsigned.apk"
+
+# ADB_SERIAL selects the device when several are attached (adb devices).
+ADB="adb${ADB_SERIAL:+ -s $ADB_SERIAL}"
+
+if [ "$INSTALL" = "1" ]; then
+	echo "=== install ==="
+	$ADB get-state >/dev/null 2>&1 || die "no adb device (connect the phone; set ADB_SERIAL if several are attached)"
+	$ADB install -r "$REPO/cmd/passgo-gui/passgo-gui.apk"
+fi
+
+echo "=== DONE: $REPO/cmd/passgo-gui/passgo-gui.apk ==="