Given Apple’s closed ecosystem and increasing security measures (Lockdown Mode, anti-exploit patches every 2 weeks), it is unlikely that a true Game Guardian equivalent will ever exist for non-jailbroken iPhones.
A memory editor that can be "injected" into a specific game's IPA before installation. IPA No Jailbreak (Sideload)
Possible future scenarios:
Are you an avid gamer looking to take your mobile gaming experience to the next level? Do you want to gain an edge over your competitors and access premium features without breaking the bank? Look no further than Game Guardian iOS IPA.