OldOS: Nostalgic teen re-creates iOS 4 as standalone app | Cult of Mac

Teen dev re-creates ‘nostalgic’ iOS 4 as standalone app called OldOS


What's old is new.
Photo: OldOS

The days of iOS 14 are numbered. Here in June 2021, it’s all about … err, iOS 4?

At least, that’s the case for Zane Kleinberg. While most of the Apple fanbase is focused on the newly announced iOS 15, teen developer Kleinberg painstakingly remade iOS 4 — which Apple released in 2010 — from the ground up as a standalone app. He calls it OldOS, and you can try it out for yourself today.

“What I’ve created [with] OldOS is iOS 4 beautifully rebuilt in SwiftUI,” the up-and-coming developer told Cult of Mac. “In essence, the app is something of an emulator, or perhaps, a second operating system that lives inside an app on your phone. It’s really designed to be a near-functioning, near-pixel-perfect re-creation of iOS 4.”

The birth of iOS

The fourth version of Apple’s mobile operating system — and the first to be called “iOS” instead of “iPhone OS” — iOS 4 brought notable updates back in 2010. It introduced Home screen folders, added custom wallpaper support, incorporated system-wide spellcheck and more.

Since it came before the flatter icons ushered in by Jony Ive’s controversial redesign of iOS 7, iOS 4 firmly embraced skeuomorphism. As such, it looks somewhat anachronistic today — a reminder of just how far iOS has progressed in the past decade. But if you think iOS 4 feels old to you, it likely feels a whole lot more ancient for the 18-year-old Kleinberg. He was just 7 when it launched.

Kleinberg sums up iOS 4 in one word: nostalgia.

“My first experience with any form of modern mobile technology was iOS 4,” the New York-based dev said. “It’s difficult to articulate how special of a place this piece of software has in my heart. It is what first introduced me to a passion for app development [and] tech. I think we all just like to cling to a very select number of childhood memories, and so many of mine include this operating system.”

A couple of years after iOS 4 debuted, Kleinberg — then in the fourth grade — created a homework tracker as his first app to hit the App Store. While that app is no longer available, he’s not looked back since. His chosen course when he attends college later this year? Computer science, of course.

Reverse-engineering iOS 4

Zane Kleinberg: Expect to hear more from him
Expect to hear more from Zane Kleinberg.
Photo: Zane Kleinberg

Kleinberg created OldOS using a combination of old assets such as icons and other things he had to design himself. He said he managed to re-create most of iOS 4-era apps. However, a few — like Mail, Calendar, YouTube and Messages — still have “major issues” he’s working on.

The apps vary in functionality, with some working a lot more fully than others. The Calculator app can do sums, for instance. But the Messages app (still a work in progress) just shows a notification and the user interface. In other words, OldOS is more of an interactive museum piece than a genuine, fully functional operating system. Not that Kleinberg didn’t learn a whole lot making it.

“For months, I had an iPhone 4 running iOS 4 sitting on my desk, and would go app by app, trying to [figure] out how Apple engineered them,” he said. “Since I am somewhat proficient in reverse-engineering, I would decompile the app binaries and try to look, from a more technical perspective, how Apple was building its apps. I also managed to find iOS 4 UI Kits, and was able to pop them into Photoshop and take a look.”

Other bits of Kleinberg’s OldOS project required different methods.

“For apps like Stocks and Weather, which are no longer functional, I [looked] at YouTube videos, trying to deduce as much as I could about the design,” he said. “It was just a constant process of looking at various assets over and over again, then trying to build it in SwiftUI, and then repeating until I was satisfied with that UI component.”

Why you won’t find OldOS in the App Store

Unfortunately, don’t expect to find the finished app in the App Store. Kleinberg says he’s convinced Cupertino wouldn’t accept it due to its liberal use of Apple-owned assets. Apple enforces strict guidelines on referring to its products in apps.

“This entire project is a testament to the phenomenal work of Apple teams both past and present,” Kleinberg said. “I’m just hoping this project might convince them to re-evaluate their policy even a little.”

For those who want to try OldOS, Kleinberg said it can be downloaded from TestFlight, Apple’s developer service for beta-testing apps. Or they can check out his OldOS project on Github.


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