Enlarge / Photos of iGBA that appeared on the App Store before the app was taken down. (credit: Internet Archive)

Over the weekend, developer Mattia La Spina launched iGBA as one of the first retro game emulators legitimately available on the iOS App Store following Apple’s rules change regarding such emulators earlier this month. As of Monday morning, though, iGBA has been pulled from the App Store following controversy over the unauthorized reuse of source code from a different emulator project.

Shortly after iGBA’s launch, some people on social media began noticing that the project appeared to be based on the code for GBA4iOS, a nearly decade-old emulator that developer Riley Testut and a partner developed as high-schoolers (and distributed via a temporary security hole in the iOS App Store). Testut took to social media Sunday morning to call iGBA a “knock-off” of GBA4iOS. “I did not give anyone permission to do this, yet it’s now sitting at the top of the charts (despite being filled with ads + tracking),” he wrote.

GBA4iOS is an open source program released under the GNU GPLv2 license, with licensing terms that let anyone “use, modify, and distribute my original code for this project without fear of legal consequences.” But those expansive licensing terms only apply “unless you plan to submit your app to Apple’s App Store, in which case written permission from me is explicitly required.”