Earlier this month, Apple quietly adjusted its Apple Store review guidelines, adding new language specifically states, “retro game console emulator apps can offer to download games,” marking the first time the company has allowed emulators on iOS. Hooray!

It didn’t take long for someone to take advantage of this new allowance: iGBA, a Game Boy emulator, made its debut on the App Store over the weekend, quickly topping the free apps charts. The introductory emulator seemed to play by Apple’s new rules: As piracy is, obviously, illegal, the app would only run ROMs you downloaded yourself to the Files app on your iPhone. iPhone gamers rejoiced. Then Apple removed the emulator from its marketplace, just days after it launched. iPhone gamers mourned.

While we still don’t know exactly why Apple took away iGBA, there seems to be a likely explanation—and it has nothing to do with pirated games. Developer Riley Testut took to Threads on Sunday to highlight the fact that iGBA appears to be a knock-off of their own emulator, GBA4iOS. Despite Testut not giving permission to use his code, somehow iGBA managed to pass through Apple’s strict App Review process to land on the App Store itself.

Tetsut has been trying to launch their alternative app store, AltStore, in the European Union for over a month, and plans on publishing Delta, a revised version of GBA4iOS, once that happens. With all this up in the air, Testsut says he’s particularly frustrated Apple was so quick to approve a rip-off of his app.

That said, it seems Apple took Testut’s claims seriously. I assume the company launched an investigation, and once Apple confirmed iGBA was indeed made from stolen code, it promptly removed it from the App Store.

The process seems to have followed wha tis outlined in the company’s App Review Guidelines:

Make sure your app only includes content that you created or that you have a license to use. Your app may be removed if you’ve stepped over the line and used content without permission. Of course, this also means someone else’s app may be removed if they’ve “borrowed” from your work.

There’s a lot to be learned from this experience. First, don’t steal. It’s wrong, and Apple will boot you from the App Store for doing it, no matter how successful you are. Second, and more pertinent to most of us, is to not download the first emulator to hit the iOS App Store. Tetsut says iGBA was rife with ads and tracking, which means those happy retro gamers playing Pokémon on their iPhones this weekend likely had their privacy breached. There’s no evidence iGBA was malicious, but it’s easy to imagine another emulator app sneaking onto the App Store with bad intentions.

While you can’t download iGBA going forward, it won’t disappear from your iPhone if you already installed it. While you can continue using it, given the situation, I’d recommend you just delete it. While this change in Apple’s policy is positive, it’s important to take a breath: I’m sure Apple is going to be even more stringent with its emulation reviews going forward, but it might be best to wait until an emulator has been further vetted before diving into your favorite retro game.