Android developer portal with tools, libraries, and apps

Dolphin is an emulator for running GameCube, Triforce and Wii games on Windows/Linux/OS X systems and recent Android devices.

This is the Android port of an NES emulator written in Go.

Android Game Boy Emulator written in Java.

ScummVM is a program which allows you to run certain classic graphical point-and-click adventure games, provided you already have their data files.

Currently there are libretro implementations for systems such as SNES, NES, GBA, GB/GBC, Genesis, and even arcade games (Final Burn Alpha).