Provenance is the best GBA Emulator for iOS which supports all kinds of ROMs for Game Boy Color, Game Boy Advance, Sega Genesis, Game Gear, Famicom, and more. It has multiple features apart from its main functions. It allows the user to save and load games at any point in time. Manage the on-screen controller, its opacity, its size, and more.
Also, read Best game hacking apps for Android.
You are free to choose from portrait and landscape orientation, that best suits you. You can directly download game ROMs from your mobile and import them into Provenance Emulator and enjoy your favorite games without any difficulty. Provenance Emulator provides you with full control over it. You can easily change and modify each and everything that you want.