This is an open-source emulation project based on Libretro. It's completely free, focused on ease of use and good user experience.

Fast game engine that lets you play games very smooth.
Quick save and restore games you will never get lost
Simple controls keyboard, giving you the best arcade game experience.
You can easily create Multiple-Disk images and easily manger your rom files.

more info :
https://github.com/libretro
https://github.com/duchengzhen/MAME4droid
https://github.com/Swordfish90/Lemuroid
https://github.com/dolphin-emu/dolphin
https://github.com/citra-emu/citra
https://github.com/hrydgard/ppsspp
https://github.com/AetherSX2/AetherSX2
https://github.com/jpd002/Play-
https://github.com/flyinghead/flycast
https://github.com/Yabause/yabause
https://github.com/yuzu-emu/yuzu
https://github.com/TeamAmaze/AmazeFileManager
https://github.com/mozilla-mobile/firefox-android
https://github.com/xenia-project/xenia


Features:
- Personalize the placement and size of screens, for portrait and landscape modes.
- High quality game graphics and sound like on the original device.
- Increase emulation speed with fast forward.
- 99.9% compatibility on consoles games
- Customizable on-screen buttons (size and position)
- Fast game speed as on the original device.
- Save and load game state easily.
- Optimized code to save battery life
- Full support for physical controllers
- Roms File Mangaer
- Multiple-Disk image Creator
- Saves your battery as much as possible
- Support for zipped/7z/rar ROMs
- Prefect Run PS2 Rom on X64 ARM devices


note: You can view the license for this app by "Third Party Notices" in the settings menu.