An ad-free, one-time-paid Android file manager. It browses and manages the files on your device — locally, with no ads, no account and no analytics.

Nothing ever leaves the device: the app declares no network permission and contains no advertising or tracking SDKs.

Working title. The display name and the store listing are decided before the first Play upload (see docs/ROADMAP.md, M10). The applicationId is already fixed and can never change after the first release.

Status

M8 — localisation groundwork: done. Every user-visible string is in resources with real plurals, the audit's one genuine miss (the details sheet showing an enum name) is fixed, and the debug build's pseudo-locale makes the check mechanical. See the README's Localisation section.

Tech stack

Area	Choice
Language	Kotlin 2.4.10 (using AGP 9 built-in Kotlin)
UI	Jetpack Compose, BOM 2026.06.01, Material 3
Build	Gradle 9.3.1, Android Gradle Plugin 9.1.0
Storage access	`MANAGE_EXTERNAL_STORAGE` ("All files access") with a Storage Access Framework fallback
Archives	Apache Commons Compress (pure Java — no NDK)
SDK levels	`compileSdk`/`targetSdk` 36, `minSdk` 26

targetSdk is 36 because Google Play requires new apps and updates to target Android 16 (API 36) from 31 August 2026.

Project layout

app/src/main/java/de/softwareapp_hb/filemanager/
├── core/      Pure-Kotlin engine (no Android imports!) — paths, sorting, formatting,
│              search matching, copy/move planning, conflict policy
├── data/      Storage backends (all-files access + SAF), volumes, bookmarks,
│              file operations, archives, deletion
├── domain/    Browser + operation controllers, models, permission state
├── service/   Foreground service for long-running file operations
├── ui/        Compose theme, browser screen, components, ViewModels
└── text/      Domain enum → string-resource mapping
app/src/test/java/…            JVM unit tests for the core engine

core/ deliberately has no Android dependencies, so the trickiest logic is covered by fast JVM tests.

Building

Prerequisites:

JDK 17+ (JDK 25 verified)
Android SDK with platforms;android-36 and build-tools;36.0.0

# Tell Gradle where the SDK lives (this file is git-ignored)
echo "sdk.dir=$HOME/Android/Sdk" > local.properties

./gradlew :app:assembleDebug        # debug APK
./gradlew :app:testDebugUnitTest    # JVM unit tests for the engine
./gradlew :app:lintDebug            # Android Lint
./gradlew :app:bundleRelease        # Play upload bundle (.aab)

Release signing is optional and driven by a git-ignored keystore.properties (see keystore.properties.example); without it the release build still runs R8/minification but produces an unsigned artefact.

Tracked in git

Source, resources and Gradle build files.
docs/ — roadmap and release documentation.
PRIVACY.md, CHANGELOG.md, and (from M10) store-assets/.

Not tracked: local.properties, keystore.properties, *.jks, build outputs.

Releasing

Release signing is driven by the git-ignored keystore.properties (see keystore.properties.example). Without that file the release build still runs R8 and resource shrinking, but produces an unsigned artefact that cannot be uploaded.

./gradlew :app:bundleRelease                      # Play upload bundle (.aab)
./gradlew :app:assembleRelease                    # APK, for local checks

# Audit what is actually shipped — in particular that there is no INTERNET permission:
$ANDROID_HOME/build-tools/36.0.0/aapt2 dump permissions \
  app/build/outputs/apk/release/app-release.apk

Read docs/PLAY_RELEASE_CHECKLIST.md before uploading. Step 4 is the one that matters most for this app: a file manager must declare "All files access" through Play's Permissions Declaration Form, and have the core purpose documented in its store description. PRIVACY.md is written to match the shipped permissions.

Localisation

All user-visible text lives in app/src/main/res/values/strings.xml, with real <plurals> wherever a count can be one, and the screen and the progress notification resolve their labels through text/TextRes.kt so the two cannot drift apart. English is currently the only locale.

Adding a language is then a file, not a refactor:

app/src/main/res/values-de/strings.xml   # same keys, translated values

Deliberately not localised, and why:

Byte units ("KB", "MB") — symbols, not words, and every file manager and the system Settings app show them the same way.
The timestamp pattern (yyyy-MM-dd HH:mm) — a fixed, sortable format; the zone is passed in explicitly rather than assumed.

Checking that nothing was missed

Two things are easy to get wrong: a literal typed into a composable, and showing an enum constant directly (FileKind.name puts untranslatable English on screen — the details sheet used to do exactly that). The mechanical check is the pseudo-locale:

./gradlew :app:assembleDebug
# Settings > System > Languages > English (XA), then launch the debug build.

The debug build type sets isPseudoLocalesEnabled = true, so every string that came from strings.xml renders accented and bracketed ([Îmàgé]). Anything that looks normal is a string that never went through resources. The release build is unaffected.

One caveat: Google Play's automatic translation translates your store listing, not the app UI. Translated UI text has to be supplied in values-<locale>/.

Known limitations

"Open with" and Share only work in the all-files mode. A SAF path is relative to the granted tree rather than a filesystem path, so it cannot be handed to FileProvider.
RAR and 7z are refused, not supported — they need native code, which this project deliberately does not ship.
Archive extraction does not restore original timestamps or permissions, and there is no archive encryption or password support.
Cancellation happens between entries, so a single very large file finishes before a stop is honoured.
View state is not persisted across process death (SavedStateHandle is not wired up).
Long-press multi-select could not be driven from adb on the MIUI test device, so the compress/extract buttons want a manual pass (see docs/EDGE_CASE_TESTING.md).
The display name is still the working title — decided before the first upload (M10).

README.md

File Manager