A physics engine should not be platform specific. That said, you probably want something light for Android.
- You can try BEPU Physics.
- I vaguely recall someone extended Farseer to handle 3D for MonoGame, but I don’t remember who.
- I noticed you also posted in Any 3D physic engine for Monogame ?. The DigitalRune library mentioned there has been open-sourced so check it out! https://github.com/DigitalRune/DigitalRune
- There’s also Jitter. I don’t really know anything about that, but a fork of it is used in Protogame which makes me think it’s pretty good