iOS, however, uses a completely different architecture and a strict "sandboxing" model. Applications on an iPhone or iPad are isolated from each other, meaning one app cannot typically read or modify the memory of another. Because of this, a direct port of GameGuardian as an IPA (iOS App Store Package) is technically unfeasible for standard, non-jailbroken devices. iGameGuardian: The Closest Alternative
Instructions on to safely sideload apps. A guide on checking if your iOS version is jailbreakable . game guardian ipa file free