MG4 Simple Launcher is a simple custom home launcher designed for the MG4 head unit (1920×720, landscape). It is part of the MG4 app suite (MG4Control, MG4Tasker, MG4ABRPUploader, MG4 Swipe Launcher) and shares its dark Material 3 theme, its CI/CD and security gates, and its two-channel release model.
⚠️ This software runs on a vehicle head unit. Do not interact with it while driving. Read DISCLAIMER.md before installing. This independent project is not affiliated with SAIC Motor or MG Motor.
- Screenshots
⚠️ Upgrading from an earlier build — please read- Features
- Channels
- MG4Suite releases
- Changing a pinned app
- Second screen (system info)
- Building
- Project documents
- Security
- Contributing
- Legal
The application id changed from com.tommasov.mg4simplelauncher to
com.mg4.launcher.simple, and the app is now signed with the MG4 suite platform
key (the same key as MG4Control and MG4Tasker). Either change alone forces a fresh
install: uninstall the previous version first, then install the new one, then set it
as the default home again from Android settings. Favorites are stored per-app, so they are
reset.
- Swipeable two-page home: a horizontal carousel (
ViewPager2). Swipe left/right between the launcher home (page 1) and a system-info screen (page 2). A SAIC-style bar indicator at the bottom centre shows the current page. - Favorite cards (page 1): a grid of cards, each launching one app of your choice — up to 12. Tap a card to open its app; long-press to replace or remove it. The last tile is always a +, which is how a new app is added. Rows and columns follow the number of cards (1 row up to 4 apps, 2 rows up to 8, 3 rows beyond), so the tiles stay as large as the count allows.
- Fourth column:
- All apps (top card): every launchable app, in a grid.
- Two fixed shortcuts (bottom card): the Android 9 default Files and Settings apps, side by side as icons.
- System apps & updates: inside the All apps drawer, the header carries a
System apps button (only system apps,
FLAG_SYSTEM) next to Check for updates (unstable channel only), plus a back button to return home. - MG4Suite manager: the MG4Suite button detects suite apps and, on unstable, checks their GitHub releases for missing installs and updates with changelogs.
- MG4 suite theme: dark Material 3 on the shared
mg4_*colour and spacing tokens, with the suite's 72 dp touch target. Dark is imposed rather than following the system: the screen faces the driver at night, and a light background filling the windscreen is glare, not a preference. - Persisted favorites: the chosen apps are saved across reboots (a home page built with an older three-slot version is migrated on first launch).
Two build flavors, like the sibling apps:
- stable — tagged releases, no self-update. The updater class is not in the
APK and the manifest declares no
INTERNETpermission. Installed offline, from a USB stick. - unstable — a pre-release published on every push to
master, with OTA so testers stay current without manual work. Application idcom.mg4.launcher.simple.unstable, so it installs beside a stable build (only one of the two can be the default home at a time).
The unstable updater downloads to private cache, validates https and the GitHub allowlist
at every redirect, verifies the running app's certificate, then installs automatically via
pm. The suite manager uses the same path after explicit confirmation. Cached APKs are
always deleted. See
SECURITY.md.
From All apps → MG4Suite, stable lists installed suite apps without network access.
Unstable checks MG4Control's latest online release and each other app's rolling unstable
GitHub prerelease, compares the numeric version carried by the APK asset name, and shows
the changelog before download. Repositories and package names use a fixed allowlist. Every
downloaded APK must carry the launcher's signing certificate and match its catalogue entry.
Long-press a card to choose between replace and remove; replacing opens the app picker. To add one, tap the trailing + tile and pick an app. Your choices are saved across reboots.
Swipe right from the home to reach the system-info page (SystemInfoFragment /
res/layout/fragment_system.xml). It shows live, permission-free stats that refresh
while the page is visible:
- Device: manufacturer + model, Android version (release · API), uptime, and the installed launcher version.
- Memory: used / total RAM.
- Storage: free / total internal storage.
- Network: active connection type (Wi-Fi / mobile / Ethernet / offline) and, on Wi-Fi, the negotiated link speed.
Standard Android project (Java + Kotlin, AGP 8.6, Gradle 8.7, minSdk 28 /
targetSdk 34). JDK 17 is required and pinned in mise.toml.
mise run build # stable debug APK
mise run build-unstable # unstable debug APK (OTA enabled)
mise run test # JVM unit tests, both channels
mise run permissions # permission-drift gate, same check the CI runs
Or directly:
./gradlew assembleStableDebug
./gradlew assembleUnstableDebug
APKs land under app/build/outputs/apk/<channel>/debug/.
To sign locally, in gradle.properties (never committed) or as environment
variables — the same MG4 suite platform key used by MG4Control and MG4Tasker:
mg4.keystore=/path/to/platform.keystore
mg4.keystore.password=…
mg4.key.alias=platform
mg4.key.password=…
mise run emulator-setup # one-off: SDK images + both AVDs (needs /dev/kvm)
mise run emulator-screen # API 28 at MG4 panel geometry — the useful one for UI work
mise run emulator-car # API 33 Automotive — automotive system UI, wrong OS version
mise run run # build, install and start on whatever device is connected
mise run emulator-stop
Neither profile is faithful on both axes: the vehicle runs AAOS 9 (API 28), but Google
publishes no Automotive system image below API 33. The screen profile is the one that
matters here — the project targets 1920x1080 @ 160dpi
(SWI68-29958-1300R69). The 1920×720 quoted above is the usable app area left under the
system UI; set EMU_HEIGHT=720 in mise.toml and re-run emulator-setup to model that
instead.
The AVDs are named per repo (mg4simple-*, mg4swipe-*), matching the mg4tasker-* /
mg4abrp-* convention used by the sibling projects.
mise run run starts the launcher as an ordinary activity — that does not make it the
default home. Use mise run set-home (or press Home on the emulator and pick it in the
chooser) to exercise it as the real launcher.
| Workflow | Trigger | Blocking |
|---|---|---|
tests.yml |
push / PR | JVM unit tests, both channels |
security.yml |
push / PR | permission-drift gate + gitleaks; mobsfscan / semgrep / OWASP are informational SARIF |
unstable.yml |
push to master |
builds and publishes the rolling unstable pre-release |
release.yml |
v* tag |
builds, checks, and publishes the stable APK |
Every uses-permission must be listed with a justification in
.github/security/permission-allowlist.txt, or the build fails.
- SECURITY.md — threat model, what the OTA path guarantees, how to report a vulnerability privately
- DISCLAIMER.md — no warranty, no liability, and what running this on a vehicle head unit means concretely
- CONTRIBUTING.md — ground rules and the checks to run before a PR
- LICENSE.md — this is a fork of an unlicensed upstream project; read it before reusing anything
- AGENTS.md — architecture notes for contributors and coding agents
See SECURITY.md for the threat model and how to report a vulnerability privately.
Read CONTRIBUTING.md before opening a pull request. In short: this code runs in a moving vehicle, so changes stay small, carry tests, and say in the diff what would break without them. Anything touching the interface follows DESIGN.md.
The full text lives in DISCLAIMER.md. In short:
This project is provided for study and educational purposes only. It is an experimental, non-commercial project and is not affiliated with, endorsed by, or supported by SAIC, MG, or any vehicle manufacturer.
The software is provided "as is", without warranty of any kind, express or implied. The author accepts no liability for any direct, indirect, incidental, or consequential damage of any kind — including but not limited to damage to the vehicle, its infotainment system, software, or data, loss of functionality, or safety-related consequences — arising from the installation or use of this app. You use it entirely at your own risk. Do not interact with the app while driving.
All graphic resources, trademarks, and brand names belong to their respective owners and are used here for study purposes only.