Principia
Principia is a free, open-source game for Android. Physics-based sandbox building game. It has 420 GitHub stars and is released under the BSD-3-Clause license, and you can install it from F-Droid.
- Android
- Games
- Actively maintained
About Principia
Principia is a physics-based sandbox building game. Build and play advanced contraptions, circuiting, minigames, robot adventures and more. The sandbox contains 200+ different objects ranging from basic wooden building blocks to circuitry, electrical and mechanical components, small robots you can control and fight against, and a LuaScript object featuring Lua scripting that can interact with the world. Build a controllable car, a calculator or make your own game with circuitry or in Lua. The Principia community site contains tens of thousands of creative levels made by players like you, from impressive contraptions to amusing games all for you to browse through and play.
Privacy and F-Droid
F-Droid builds Principia from its published source code and flags anti-features such as ads, tracking or reliance on non-free services.
- Relies on a non-free network service
Screenshots
Screenshots from the app's F-Droid listing.
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What is Principia?
Principia is a free, open-source game for Android. Physics-based sandbox building game. It has 420 GitHub stars and is released under the BSD-3-Clause license, and you can install it from F-Droid.
Is Principia free and open source?
Yes. Principia's source code is public on GitHub under the BSD-3-Clause license, which is OSI-approved or FSF-free. F-Droid flags these anti-features on its latest build: relies on a non-free network service.
How do I install Principia?
You can install Principia from F-Droid (package com.bithack.principia); the links are on this page. Its GitHub repository also publishes releases (latest: 2026.09.19).
Is Principia still maintained?
The repository's most recent commit was on Sep 23, 2026. Its F-Droid listing was last updated on Aug 19, 2026. appsgit only lists apps whose repository had a commit in the last six months.


