Real Android apps, hand-built APKs, kilobyte-scale.
Pure Java · Android SDK · No Gradle · No AndroidX · No Kotlin
English · Русский · Quick start · Projects · Build chain · Structure
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Two playable games. Two APKs under 21 KB. Zero build-system dependency.
Built by a solo dev · assembled with five command-line tools
Note
No Gradle project inside. These apps are compiled and packaged by hand: aapt2 -> ecj -> d8/R8 -> zipalign -> apksigner. There is no build.gradle, no Android Studio project, and no AndroidX — just Java source, the platform SDK, and a handful of command-line tools.
TinyAPK Lab is a small, curated collection of Android apps written in plain Java against the raw Android SDK APIs. No Gradle, no Kotlin, no AndroidX, no game engine — just SurfaceView, Canvas, and a build chain assembled entirely from command-line tools. The point is to show how small, transparent, and portable a real, installable Android app can be.
Tip
Release APKs stay under 21 KB. An empty "Hello World" Android Studio project typically ships at 1.5–3 MB before a single line of logic is written. These apps are 70–150× smaller — and fully playable.
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Signed, installable release builds in the 16.8–20.9 KB range are committed straight into the repo. |
- Quick start
- Projects
- Screenshots
- Build chain
- Tech stack
- Repository structure
- Why this exists
- Documentation
- Principles
- License
Every project already ships a signed release build in its build/ folder:
adb install "Tetris/build/LowBlocks-release.apk"
adb install "Sandbox/build/LowSand-release.apk"No Gradle, no project to open in an IDE — just the platform build tools on your PATH:
aapt2 compile -o compiled/ res/**/*
aapt2 link -o app-unsigned.apk -I android.jar --manifest AndroidManifest.xml compiled/*.zip
ecj -d classes -classpath android.jar src/**/*.java
d8 --release --output . classes/**/*.class
zip -j app-unsigned.apk classes.dex
zipalign -f 4 app-unsigned.apk app-aligned.apk
apksigner sign --ks debug.keystore --out app-release.apk app-aligned.apkFull, project-specific step-by-step notes live in manual-build/, including R8 shrinking guidance (EN / RU).
| Project | What it includes | Build output |
|---|---|---|
 Tetris |
Swipe-based classic Tetris — 7 tetrominoes, ghost piece, wall kick, scoring, levels, next-piece preview. | LowBlocks.apk — 16,811 BLowBlocks-release.apk — 16,811 B |
 Sandbox |
Falling-sand simulation — powders, water, seeds, heat, steam, simple farming, cooking reactions. | LowSand.apk — 20,907 BLowSand-release.apk — 16,811 B |
 Build guides |
Manual build notes for aapt2 -> ecj -> d8/R8 -> zipalign -> apksigner, plus R8 shrinking guidance. |
Documentation |
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Tetris Minimal UI, ghost piece, scoring, level flow. |
Sandbox Particles, heat, farming, cooking. |
flowchart LR
SRC["Java source<br/>+ resources"] --> AAPT["aapt2<br/>compile & link"]
AAPT --> ECJ["ecj<br/>compile to .class"]
ECJ --> D8["d8 / R8<br/>.class -> .dex"]
D8 --> ZIP["zipalign<br/>4-byte alignment"]
ZIP --> SIGN["apksigner<br/>sign"]
SIGN --> APK["Signed APK<br/>16.8-20.9 KB"]
No Gradle daemon, no dependency resolution, no annotation processors — five tools, one direction, a fully inspectable output at every stage.
Java 8 — language
Android SDK APIs — platform, no support libraries
SurfaceView + Canvas — rendering, no game engine
aapt2 -> ecj -> d8/R8 -> zipalign -> apksigner — build chain
Deliberately not used: Gradle, Kotlin, AndroidX/Jetpack, external UI or game frameworks, third-party dependencies.
.
├── README.md # this file (English)
├── README.ru.md # Russian version
├── PROGUARD_README.md # R8 / ProGuard shrinking guide (EN)
├── PROGUARD_README.ru.md # R8 / ProGuard shrinking guide (RU)
├── LICENSE # MIT (EN)
├── LICENSE.ru.md # MIT (RU)
├── THIRD_PARTY_TOOLS.md # notice on Android SDK / build tools licenses (EN)
├── THIRD_PARTY_TOOLS.ru.md # notice on Android SDK / build tools licenses (RU)
├── .github/
│ └── assets/
│ ├── banner.svg
│ ├── badges/
│ └── icons/
├── docs/
│ └── images/
│ ├── tetris-shot-v2.jpg
│ ├── sandbox_en.jpg
│ └── sandbox_ru.jpg
├── manual-build/ # manual build guides
│ ├── README.md
│ ├── SKILL.md
│ ├── proguard/SKILL.md
│ └── tetris/SKILL.md
├── tools/ # platform build binaries & keystores
│ └── windows/
├── Tetris/
│ ├── README.md
│ ├── build.ps1
│ └── build/
└── Sandbox/
├── README.md
├── build.ps1
└── build/
Most Android tutorials start with Gradle, AndroidX, and a few hundred megabytes of tooling before a single pixel is drawn. This repository goes the other way: how small, transparent, and dependency-free can a real, installable Android app get if you build it by hand, one tool at a time?
It works both as a reference for the manual aapt2 -> d8 -> apksigner pipeline and as a proof of concept that kilobyte-scale, Gradle-free Android apps are still entirely possible.
| Tetris project |
Gameplay, controls, and source layout |
| Sandbox project |
Particle rules, farming, and cooking mechanics |
 Manual build notes |
Step-by-step aapt2 -> ecj -> d8/R8 -> zipalign -> apksigner |
 R8 / ProGuard guide |
Shrinking, obfuscation, and size-reduction notes |
 Third-party tools notice |
Licensing notes for Android SDK / build tools |
- Minimal by mandate. If it needs Gradle, AndroidX, or a dependency manager, it doesn't belong here.
- Transparent. No obfuscated build magic — every step of the pipeline is a plain command you can run yourself.
- Portable. Builds from a terminal, with nothing more than the Android SDK command-line tools and a JDK.
- Small by default. Every release APK is committed to the repo so you can see exactly what "kilobyte-scale" means.
Original code and documentation are released under the MIT License (EN / RU). A separate tooling notice (EN / RU) clarifies that these projects are built using the Android SDK and platform build tools, which remain under their own respective licenses.
TinyAPK Lab · real Android apps, kilobyte-scale
MIT License · See LICENSE for details