diff --git a/.github/workflows/formulus-android.yml b/.github/workflows/formulus-android.yml
index 919a9e606..5c020c844 100644
--- a/.github/workflows/formulus-android.yml
+++ b/.github/workflows/formulus-android.yml
@@ -75,7 +75,7 @@ jobs:
           retention-days: 7
 
   build-android:
-    name: Build Formulus Android APK
+    name: Build Formulus Android
     runs-on: ubuntu-latest
     needs: build-formplayer-assets
     permissions:
@@ -121,6 +121,16 @@ jobs:
         working-directory: formulus
         run: pnpm run vendor:notifee
 
+      - name: Apply FOSS Android patches (match F-Droid init)
+        if: github.event_name != 'pull_request'
+        working-directory: formulus
+        run: pnpm run patch:android-foss
+
+      - name: Generate injection script (match F-Droid init)
+        if: github.event_name != 'pull_request'
+        working-directory: formulus
+        run: pnpm run generate
+
       - name: Set up Java
         uses: actions/setup-java@v4
         with:
@@ -166,6 +176,11 @@ jobs:
         working-directory: formulus/android
         run: ./gradlew assembleRelease --no-daemon
 
+      - name: Build release AAB for Play Store (main/dev/release)
+        if: github.event_name != 'pull_request'
+        working-directory: formulus/android
+        run: ./gradlew bundleRelease --no-daemon
+
       - name: Upload APK artifact
         uses: actions/upload-artifact@v6
         with:
@@ -173,11 +188,20 @@ jobs:
           path: |
             formulus/android/app/build/outputs/apk/**/**/*.apk
 
+      - name: Upload AAB artifact
+        if: github.event_name != 'pull_request'
+        uses: actions/upload-artifact@v6
+        with:
+          name: formulus-android-aab-${{ github.event_name }}-${{ github.run_id }}
+          path: |
+            formulus/android/app/build/outputs/bundle/release/*.aab
+
       - name: Upload APK to GitHub Release
         if: github.event_name == 'release'
         uses: softprops/action-gh-release@v2
         with:
           files: |
             formulus/android/app/build/outputs/apk/**/**/*.apk
+            formulus/android/app/build/outputs/bundle/release/*.aab
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/formulus/android/ANDROID_RELEASE.md b/formulus/android/ANDROID_RELEASE.md
new file mode 100644
index 000000000..f01fe14ea
--- /dev/null
+++ b/formulus/android/ANDROID_RELEASE.md
@@ -0,0 +1,49 @@
+# Android release: Google Play and F-Droid
+
+Formulus ships from one FOSS codebase. Play Store and F-Droid use the same dependency patches and build steps; only packaging and version-code handling differ.
+
+## Shared release prep
+
+1. Bump `versionName` / `versionCode` in `app/build.gradle` (or run `pnpm run sync:version` from `formulus/`).
+2. From `formulus/`:
+   ```sh
+   pnpm install --frozen-lockfile
+   pnpm run vendor:notifee
+   pnpm run patch:android-foss
+   pnpm run generate
+   ```
+3. Tag the release commit on the upstream repo, e.g. `v1.0.2` (F-Droid update checks use stable tags matching `v[\d.]+$`).
+
+## Google Play
+
+- **Artifact:** Android App Bundle (AAB) — `./gradlew bundleRelease` in `formulus/android/`.
+- **CI:** GitHub Actions builds `bundleRelease` on `main`, `dev`, and GitHub Releases; uploads the AAB artifact and attaches it to releases.
+- **versionCode:** Uses `defaultConfig.versionCode` in the AAB (single code per release).
+- **Signing:** See [SIGNING_CONFIG.md](./SIGNING_CONFIG.md). CI uses repository secrets; local builds use `android/local.properties`.
+
+Optional split APKs for sideloading or GitHub Release assets:
+
+```sh
+./gradlew assembleRelease
+```
+
+Split APKs use per-ABI version codes: `baseVersionCode + abiOffset` (2–5 when base is 2).
+
+## F-Droid
+
+- **Artifact:** One APK per ABI, built from source by F-Droid.
+- **Metadata:** `fdroiddata/metadata/org.opendataensemble.formulus.yml` — four builds with `abiFilters` and explicit `versionCode` per ABI.
+- **Gradle:** Pass `-PabiFilters=<abi>`; F-Droid prebuild strips custom APK naming and sets `versionCode = $$VERCODE$$`.
+- **Init steps:** Same as shared prep above (`vendor:notifee`, `patch:android-foss`, `generate`).
+
+After tagging, update the metadata commit SHA and version fields, then open/update the fdroiddata merge request.
+
+## Version codes
+
+| Channel | versionCode |
+|---------|-------------|
+| Play AAB | `defaultConfig.versionCode` |
+| Play / local split APKs | base + ABI offset (armeabi-v7a +0, arm64-v8a +1, x86 +2, x86_64 +3) |
+| F-Droid per-ABI build | Set in metadata prebuild (`$$VERCODE$$`) |
+
+When bumping a release, increase `defaultConfig.versionCode` and update F-Droid build entries (and `CurrentVersionCode`) to match the highest per-ABI code.
diff --git a/formulus/android/app/build.gradle b/formulus/android/app/build.gradle
index 7c869c946..74cc1a770 100644
--- a/formulus/android/app/build.gradle
+++ b/formulus/android/app/build.gradle
@@ -87,7 +87,10 @@ def enableProguardInReleaseBuilds = false
  */
 def jscFlavor = 'io.github.react-native-community:jsc-android:2026004.+'
 
-def abiVersionCodes = ['armeabi-v7a': 1, 'arm64-v8a': 2, 'x86': 3, 'x86_64': 4]
+def perAbiVersionCode(int baseVersionCode, String abi) {
+    def offsets = ['armeabi-v7a': 1, 'arm64-v8a': 2, 'x86': 3, 'x86_64': 4]
+    return baseVersionCode + offsets.get(abi, 0) - 1
+}
 
 android {
     ndkVersion = rootProject.ext.ndkVersion
@@ -158,8 +161,7 @@ android {
             variant.outputs.each { output ->
                 def abi = output.getFilter(com.android.build.OutputFile.ABI)
                 if (abi != null) {
-                    output.versionCodeOverride =
-                        (100 * defaultConfig.versionCode) + abiVersionCodes.get(abi, 0)
+                    output.versionCodeOverride = perAbiVersionCode(defaultConfig.versionCode, abi)
                 }
             }
         }