"This is *exactly* what I’ve been hoping for since launching AltStore!" — Prolific developer celebrates Apple's massive EU App Store overhaul in exclusive interview

Delta on iPhone playing a SEGA Genesis game
(Image credit: Future / Apple)

Apple recently announced huge changes for developers in the EU in regards to how they can distribute apps with 17.4, but there’s one developer who’s happier about it than most.

Riley Testut is the creator of Delta, an emulator that allows you to play games from NES, Game Boy, Nintendo DS, and Nintendo 64 while being able to use cheats, customized skins, and more. Alas, it's long been a tricky app to get installed on your best iPhone. Since the app launched in 2020, the app has required Testut's Altstore software — a process that requires loads of steps to get working. Now, however, with Apple’s upcoming changes, it’s about to get much easier to install Delta through AltStore — at least in the EU.

We previously spoke to Testut in 2023 about what he’d like to see from Apple and 'sideloading', a process of installing third-party apps that aren't available on the Apple App Store. While Apple isn’t introducing sideloading to the iPhone in the EU, it is going to allow developers to create marketplaces outside of the App Store: But not without some extra requirements.

After Testut shared a series of posts on Mastodon reacting to the news, iMore spoke to him once again about what Apple’s change of stance means for Delta and AltStore going forward.

The aftermath of Apple’s announcements

“Honestly, extremely overwhelmed!” Testut exclaimed. “I didn’t expect Apple to release so much information at once, so it took me a second to digest everything. Once I had some time though, I was ecstatic! This was more or less *exactly* what I’ve been hoping for since launching AltStore almost 5 years ago, and it was incredibly surreal reading through all the documentation.”

Indeed, it looks like you’ll be able to use both Delta and AltStore in the EU with no issues once iOS 17.4 is released. If you run Delta on an iPhone, you may need to enable a ‘JIT function’, which essentially allows the graphical part of an iPhone’s A-series chip to use as much power as needed to run these emulated games at full speed. With Apple’s changes, this required setting will be irrelevant: “Thankfully, Delta should be able to emulate all included systems without issues! This is because none of the included systems require JIT, unlike newer systems like GameCube or Wii.“

There has been plenty of discussion on the social platform Mastodon about these announcements, where many developers now reside after jumping ship from Twitter (now X). Testut is happy with what was announced: “Most of what Apple announced was stuff we’ve been anticipating for a while, such as approving companies to become alternative marketplaces based on strict criteria, requiring all sideloaded apps to go through a marketplace, etc,” he explained. “If anything, I was surprised by the stuff we didn’t see; for example, I expected Apple to still require a commission on all payments from alternative marketplace apps, and that didn’t happen.”

What could be improved?

Rogue Squadron in Delta on iPhone

(Image credit: Future / Apple)

For everything Apple announced, there were some things that Testut thinks could do with some adjustments. “I think the Core Technology Fee requirements could use some slight tweaking. Specifically, I think free apps should be completely exempt from this fee, otherwise, a free app going viral overnight could completely bankrupt an indie developer.“

Apple must abide by the DMA changes set out by the EU by March 5th — but the company has already unveiled its plans six weeks before the deadline. With Apple’s Vision Pro headset launching in a few days, we put it to Testut that this may have been an intentional move on Apple’s part. “I do think there’s some intentional planning here. Apple wouldn’t want to ruin the hype of pre-orders by announcing these changes last week, and by doing it now they can let the news die down before Vision Pro launches next week and people talk about that instead,” Testut explains.

“Regarding Delta, it’s currently on TestFlight and supports visionOS, though I’ve also started prototyping a native visionOS port to experiment with some new ideas. But it still won’t be allowed in the actual App Store, and I’m not yet sure if it’ll be possible to sideload apps to Vision Pro with AltStore.”

An Epic Battle to come?

Delta emulator in visionOS

(Image credit: Riley Testut)

Some developers, such as Steve-Troughton Smith, feel the opposite in regards to developer’s options in the EU thanks to these changes. Others such as Mozilla, maker of the web browser Firefox, are less than pleased — explaining that the changes could stifle an app’s revenue in the EU. This could degrade the experience that Apple has offered users since the App Store was made available in 2008 — but Testut is neutral on this. “Overall, I think Apple has done a great job minimizing the negative impacts these changes could have on consumers. The requirements are stringent enough that for apps already in the App Store, there’s not much incentive to leave. That would be the worst-case scenario in my opinion, because then users would be forced to use alternative marketplaces just to install their current apps,” Testut explains.

“However, we do have to see how this plays out to know for sure. If a company like Epic or Meta is successful in getting major developers to leave the App Store for their marketplace, then that would absolutely degrade the iOS experience. I just personally think that’s unlikely given Apple’s restrictions.”

Indeed, with these changes, and a new API called MarketplaceKit, which enables developers to create their own store in the EU, there could be another golden age of apps, just like the early days of the App Store. Testut is unsure about this, but hopeful that it’s at least a possibility that this could occur. “Hard to say, but I think it’s very possible we’ll see an influx of completely new apps from indie developers now that there’s no app review to hinder creative ideas!”

Delta with Genesis and Nintendo DS running on iPhone

(Image credit: iMore)

Finally, Delta has recently seen some big improvements, such as AirPlay support from an iPhone to Apple TV — so if you’re playing Donkey Kong Country 2 on your iPhone, you can continue playing it on your TV through Apple’s set-top box.

With these upcoming changes in the EU, Testut has no plans to slow down. “It’s definitely motivated me to keep working on Delta — but there’s so much I need to do with AltStore to make it an official app marketplace that my hands are tied for now! Once we’ve made it to March though, would love to finally focus more on Delta!“

Daryl Baxter
Features Editor

Daryl is iMore's Features Editor, overseeing long-form and in-depth articles and op-eds. Daryl loves using his experience as both a journalist and Apple fan to tell stories about Apple's products and its community, from the apps we use everyday to the products that have been long forgotten in the Cupertino archives.


Previously Software & Downloads Writer at TechRadar, and Deputy Editor at StealthOptional, he's also written a book, 'The Making of Tomb Raider', which tells the story of the beginnings of Lara Croft and the series' early development. He's also written for many other publications including WIRED, MacFormat, Bloody Disgusting, VGC, GamesRadar, Nintendo Life, VRV Blog, The Loop Magazine, SUPER JUMP, Gizmodo, Film Stories, TopTenReviews, Miketendo64 and Daily Star.