Sega Genesis/Mega Drive, Sega CD, and Master System/Mark III emulator is a fork of the excellent MD.emu.
This is functionally same as MD.emu but free so that users who don't have access to paid apps (such as Android users in China) can download.
You will find detailed descriptions at the MD.emu site at
Other general information about this emulator is available at
This emulator is under GPL license, You can find the source codes at