GBA4iOS is a GBA emulator for iOS devices that is the easiest platform to play retro games on the iPhone and iPad. Unfortunately, Apple doesn’t allow GBA games on the iPhone, so people jailbreak their iPhone and iPad to play Game Boy Advance games. However, now you don’t need to jailbreak, or follow the awkward procedure to play old games on iOS; download one of these emulators to play games.
Read: Hacking apps for android.
Also check the list of the game hacking app if you are interested in game hacking.
GBA4iOS is absolutely safe and secure for iOS; also, you are not jailbreaking the phone, which means your iPhone is in control of Apple’s security.