Retro game emulator Delta has quickly risen to the top of the App Store charts, following Apple’s decision to loosen App Store guidelines.
However, its growing popularity has prompted legal action from Adobe, which argues Delta's branding is too similar to its own.
Delta developer Riley Testut began his journey by experimenting with loading games onto graphing calculators before shifting his focus to iOS.
His earlier app, GBA4iOS, exploited a loophole that allowed it to run emulated games on iOS without jailbreaking devices.
Despite gaining millions of users, Apple eventually closed the loophole, forcing GBA4iOS out of business.
In response to increasing regulatory pressure to open the App Store to more competition, Apple began allowing game emulators in April, creating new opportunities for developers who previously couldn't benefit from the App Store’s huge distribution network.
Taking advantage of this opportunity, Testut launched Delta, which soared to the top of the App Store charts, maintaining its position as the No. 1 app for several weeks and achieving millions of downloads.
Even a month after its release, Delta remains popular, ranking as the No. 33 app overall on the U.S. App Store, with another game emulator, PPSSPP, securing the No. 5 spot.
Delta's Legal Issues with Adobe
Adobe recently took issue with Delta’s logo, claiming it closely resembled Adobe’s own.
The logo featured a broken triangle modeled after the Greek letter delta, which was considered by Adobe to infringe on its trademarked "A" logo.
In its latest update, Delta disclosed Adobe’s legal threat: "Adobe is threatening legal action because they think our logos are too similar — so we changed it," read the release notes.
Both logos featured a broken triangle, but Adobe's was red and white, while Delta's was purple and white. Despite the differences in color and design specifics, Adobe argued that the logos were too similar.
Delta first received a warning from Adobe’s lawyer on May 7, requesting a change to the logo to avoid infringing on Adobe’s trademark.
Adobe then set a deadline of May 17 for Delta to respond. Subsequently, the company also requested Apple to remove Delta from the App Store.
Delta responded to both Adobe and Apple, clarifying that its logo was a stylized Greek letter delta, not an "A," but decided to update the logo to avoid any legal disputes.
The new logo, now a more complex broken triangle, is seen as a temporary solution. Designed by Caroline Moore, it hilariously depicts the old logo but with the top cut off.
Testut mentioned that the app would receive another logo update with the release of Delta 1.6.
"We’re planning to update the icon again to a 'final' version — also designed by Caroline — soon," he said, adding, "We’re not too worried about brand impact in the interim."
The redesign has sparked some debate among users, with suggestions for alternatives like using the lowercase delta letter or creating custom artwork for the new brand.
Delta continues to enjoy its position as a top app on the App Store, reflecting the high demand for retro game emulators in the mobile gaming community.
