After Apple relaxed its App Store guidelines to allow game emulators, the retro game emulator Delta — an app 10 years in the making — shot to the top of the App Store charts. However, the increased attention also brought the threat of legal action, as Adobe targeted Delta for carrying a logo that closely resembled its own.
Delta’s game emulator was built by developer Riley Testut, who had started his experiments in this space by figuring out how to load games on graphics calculators, before turning to iOS. The app itself evolved from Testut’s earlier app, GBA4iOS, which used a loophole to run emulated games on iOS without jailbreaking an iPhone. Consumer demand for such an app was high — millions of people used GBA4iOS while it was available. But Apple eventually locked things down and shut down GBA4iOS.
Now, as Apple faces regulatory pressure to open its App Store to increased competition, the tech giant began allowing game emulators in April. This opened up a whole new market for developers who were previously unable to take advantage of the massive distribution power that the App Store offers. In short, Apple would rather host these apps itself than compete with alternative app stores where the apps it once banned could find traction with consumers.
Testut took the opportunity to release Delta to the public and it quickly became the No. 1 app in the App Store, topping the Apple Charts for weeks and gaining millions of downloads. More than a month later, Delta still sits pretty high as the No. 33 app overall in the US App Store. The No. 5 slot, meanwhile, is now held by yet another game emulator, PPSSPP (a PSP emulator).
However, becoming the top app on the App Store has its downsides. While a more “under the radar” app like GBA4iOS may have been overlooked, Delta’s run to No. 1 brought increased scrutiny.
According a post on MastodonAdobe went after Delta, threatening legal action because it thought Delta’s logo resembled its own.
“Adobe is threatening legal action because they think our logos are too similar — so we changed it,” the post explains. “This new icon is an inspired design by Caroline Moore (@carolinemoore@threads.net), we hope you love it as much as we do,” it read.


Both logos featured a broken triangle, similar to the Greek letter delta. The Adobe logo, however, is red and white, and its “A” is thicker and extends to the edge of the app icon. The Delta logo is purple and white, smaller and centered within the app icon. They also work in different spaces, of course, as Adobe offers a range of tools for creatives, not a way to play retro games. It is hard to argue that there would be much consumer confusion as to which logo was which.
Delta told us that it first received an email from Adobe’s attorney on Wednesday, May 7, telling the company that its app icon was in violation of Adobe’s “A” log file and asking that it be changed so that the ” rights of Adobe or the law”.
Adobe gave Delta until May 17 to respond, but then received a second email from Apple that said Adobe had asked Apple to remove the Delta app for infringing its trademark. Delta responded to both companies to explain that its icon was a stylized Greek letter delta, not an “A,” but that the logo would be updated anyway.


To avoid any legal issues, Delta introduced a new logo that looks like a broken triangle. The redesign isn’t as streamlined and clean as before, unfortunately, leading some users to suggest it could have gone a different route — like using lower case delta, for example, or having custom artwork was created as the new brand.
Testut tells us that the new app has a temporary logo on its icon, but plans to update it again when Delta 1.6 is released.
“…We plan to update the icon again to a ‘final’ version — also designed by Caroline — soon,” he said, adding that “we’re not too worried about the brand impact in the interim.”
