iOS 4 originally appeared nearly 10 years ago as Apple’s first mobile operating system to drop the iPhone OS naming convention. An 18-year-old developer has now lovingly recreated iOS 4 as an iPhone app, and it’s a beautiful blast from the past. If you never got the chance to use iOS 4, or you’re a fan of the iPhone 3G, OldOS almost flawlessly pulls off the experience of using an iPhone from a decade ago.
Real pity the beta is full as Apple really limits the numbers on TestFlight.
All of the key animations and apps work from 10 years ago.