Interview: How one developer created iOS 4 in an app

OldOS running on an iPhone 12
(Image credit: OldOS - Zane Kleinberg)

It was back in March 2010 when iOS 4 was announced, with the iPhone 4 following at WWDC later that year. Since then we’ve seen huge changes to iOS, with a modern-looking ‘flat’ redesign in iOS 7, to see widgets, third-party keyboards and even the option to change default apps also being introduced.

But there’s a growing nostalgia for software as iDOS 2 proved with getting Windows 3.1 running on an iPad before it was removed from the App Store.

However, OldOS is a new take on how iOS 4 runs on your modern iPhone, containing almost everything into one single app.

As it’s still active with plenty of features planned, we spoke to its developer Zane Kleinberg to find out why he decided to create the app, and what’s coming up.

OldOS beginnings

While some buy an old iPhone or Palm Pre smartphone from a store for nostalgia value, Kleinberg decided to create an app based off a version of iOS that inspired him to become a developer to begin with. “There’s a nostalgia component,“ he tells us, “iOS 4 was my first exposure to the platform and was what introduced me to a passion for app development.” 

“I hold iOS in high regard because of what it inspired in me down the line. Because of my love for the OS, I have a few devices that still run it, most notably an iPhone 4. I would often use this device, sometimes on days when I didn’t want a distraction, and other times just for fun. Then, it just hit me. I was sitting inside, starved for something to do, when I decided to replicate a select few elements from that device.”

Having to replicate an entire operating system is no easy feat, so we wondered just how long it took from being an idea, to becoming OldOS.

“I would say about five months. It started off rather slow, but as I built more UI elements and became more comfortable with my process, the pace started to pick up.”

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There’s one more thing

But that’s not all that Kleinberg is working on. He’s also managed to port the Snow Leopard version of Safari as an app for macOS 11 Big Sur and above. Kleinberg explains that this was mainly due to the new design Safari has this year.

“Its new design was exactly what motivated me. I had installed Monterey within the first few days of it being available and really came to loathe the Safari redesign.” Kleinberg explained.

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“Over the next month, I kept seeing so many others share similar sentiments, and decided to try out making a version I knew I adored, which was Safari 5. Aside from loving the design, I firmly believe it has one of the best UXs of any browser. Simply put, it was really well built and I thought it would be fun to juxtapose it with its modern counterpart.”

Skeuomorphin’ time for iOS 16?

Running Safari 5 in macOS 12 Monterey compared to Safari 15 is a strange experience, but it still works well, and it raised the question on whether Kleinberg could see a future where skeuomorphism, the look of what iOS was before the flat-design arrived in iOS 7, could come back to iOS in some way.

“This is a question I teeter between regularly. Skeuomorphism is extremely powerful, as it necessitates consideration of every component and user interaction.” Kleinberg told us.

OldOS running within an iPhone 12

(Image credit: OldOS - Zane Kleinberg)

“The issue though is that skeuomorphism has, what I’d deem a high barrier to entry, whereas flat design does not. I think we're already beginning to see a merger between flat design and skeuomorphism.” Kleinberg added. 

“Take the new iOS 15 Weather app - it combines flat design and the real world facilitating interactions between the two (via weather effects, etc). I think this is the direction skeuomorphism is going in and believe Apple has a grand opportunity to create something truly inspiring should they continue down this path.”

Could iPadOS see a version of OldOS?

With OldOS in heavy development with plenty of features on the way, we wanted to see whether an iPad version could be on the horizon, or even usable folders.

Folders are definitely a top priority, that should be coming soon.” Kleinberg added. 

“I’ve also been working to get Cover Flow into it, so look out for that as well. As for iPadOS, I wasn’t planning on starting that until I finished off most of the OS, but I’ve gotten so many requests for it that I’ve decided to begin working on it. It’s no small feat, various apps need to be reworked, but if all else goes as planned it could be here quite soon.”

Daryl Baxter
Software & Downloads Writer

Daryl had been freelancing for 3 years before joining TechRadar, now reporting on everything software-related. In his spare time he's written a book, 'The Making of Tomb Raider', alongside podcasting and usually found playing games old and new on his PC and MacBook Pro. If you have a story about an updated app, one that's about to launch, or just anything Software-related, drop him a line.