Build an APK on your Android phone
The short version. AppMama is an Android app that contains a complete Android build toolchain and an AI coding agent. You describe the app; the agent writes a normal Gradle project; the phone compiles it into an APK and hands it to Android's installer. Free on Google Play.
What building an APK actually takes
Turning source code into an installable Android app needs:
- A JDK to compile Kotlin or Java.
- Gradle and the Android Gradle Plugin to drive the build.
- The Android SDK build tools —
aapt2for resources,d8for dex, and the platformandroid.jar. - A signing key, because Android will not install an unsigned APK.
On a laptop, Android Studio sets all of that up. On a phone, people usually reach for Termux and assemble it by hand: a JDK from the package manager, a Gradle download, and build tools compiled for ARM, since Google only ships them for desktop x86. It can be made to work, and it breaks whenever one piece updates.
How AppMama does it
AppMama bundles an embedded Linux environment based on Termux's — with a JDK, Gradle, Node and ARM builds of the Android build tools — inside the app itself. Nothing more is downloaded after you install it from Play. Because Android 10 and later stop apps from running programs they download into their own storage, it starts those tools through the system linker, the same approach Termux uses for its Play Store build.
On top of that sits an AI coding agent — Claude Code, Codex or Grok, on your own plan — which writes the Gradle project, runs the build, reads the compiler errors and fixes them until the APK comes out. You watch it happen in a live terminal, or put the phone down.
From prompt to installed app
- Describe the app in a sentence.
- The agent creates the project and runs a Gradle
assembleDebugbuild on the phone. - The APK is signed with a debug key made on the phone.
- Tap to install; Android shows its normal install screen.
- Ask for a change and the next build installs over the old one as an update.
A first build of a new app takes a few minutes, mostly Gradle warming up; later builds of the same app are faster. You can also share the APK file to another phone.
What it is not
- Not a full IDE — you steer by asking, not by editing files.
- Not a Play Store publisher: it builds debug APKs for your own devices.
- Not offline: the agent needs to reach your AI service. The build itself is local.
Questions
Can you build an APK on an Android phone without a computer?
Yes. AppMama ships a JDK, Gradle and the Android build tools inside the app, so a full Gradle build runs on the phone and produces an APK you can install straight away.
Does AppMama need root?
No. It is an ordinary app from Google Play. Android asks you once to allow it to install the apps it builds, as it does for any app that installs APKs.
Is the APK signed?
Yes, with a debug key made on your phone, so each new version installs over the last one as an update.
Which phones can build APKs?
Android 11 or newer on a 64-bit (arm64) phone, with about 2 GB free. Most phones sold since 2020 qualify.