Here a free and Advanced Fast GBA for Android Devices. Many options and fast emulation speed which many other app don't provide.
This the best GB Advanced emu you'll ever find with a high game compatibility and an amazing screen layout and very Simple UI
This application is able to run all kinds of GameBoy games smoothly in your device, it doesn't require a very flagship hardware of device .
Super fast and smooth GBA emulation
High-level BIOS emulation, no BIOS file needed
Works in any orientation
Landscape or Portrait Orientation
Variable Scaling Modes
Backup memory and save state support
Supports games file in .gba format, optionally in ZIP, RAR, or 7Z files
Frame Skipping if needed
Custom button layout
This app does not include any ROMs but they can be downloaded from many websites as long as you already own the game.