The developer of Gameboy emulator GBA4iOS says the top-ranking version on the App Store is a fraudulent knock off of his work that Apple should not have approved.

Shortly after Apple changed its App Store rules to allow for game console emulators to be submitted, the first few are beginning to become available. However, one of them, iGBA, is now accused of being a knock-off of GBA4iOS by Riley Testut.

Posting on Mastodon, Testut goes on to say that he is not criticizing iGBA developer Mattia La Spina, only Apple. He is frustrated that "Apple took the time to change the App Store rules to allow emulators, and then approved a knock-off of my own app — even though I've been ready to launch Alt Store with Delta since March 5."

Alt Store has reportedly been in Testflight for a year. So an App Store reviewer would have had the ability and time to compare iGBA with Delta, Testut's latest version of GBA4iOS, if they knew to look.

With thousands of apps being submitted, it's easy to see how one reviewer could miss that a near-identical app was in Testflight. However, AppleInsider confirms that there are elements of iGBA that should have raised concerns at the review stage.

For instance, the app features location tracking when there is no game-related reason for it. Plus users report that the game, while free to download, is replete with ads.

Testut does make his code open-source, but there is a condition that limits the license.

"I explicitly give permission for anyone to use, modify, and distribute all my original code for this project in any form, with or without attribution, without fear of legal consequences," says his licence on Github "unless you plan to submit your app to Apple's App Store, in which case written permission from me is explicitly required."

Neither Apple nor the developer of iGBA have commented publicly.

However, this is a further example of apps, even fraudulent ones, getting on the App Store when Apple's review team should catch them. It comes, too, as Apple decries having been forced to allow alternative app stores in the EU, because it says that they are inherently unsafe.