iOS today looks nothing like the software Steve Jobs showcased during the first iPhone launch event back in 2007. Since then, it has evolved several times, receiving new features, multiple design refreshes, and more with each annual upgrade. But since these changes happened over several years, it can be difficult for us to even imagine just how much iOS has changed in the last decade alone. Thankfully, there’s a new app that will help you experience exactly what using an iPhone felt like back in 2011.

OldOS is a new iPhone app that helps you relive the good old iOS 4 days on your brand new iPhone. It promises an accurate iOS 4 experience, complete with functional versions of stock iOS apps from the time. These include apps like Maps, Safari, Weather, and iPod, among others. Along with the nostalgia-inducing apps, OldOS will also let you change your phone’s background, adjust settings, search for apps, etc., just like you would on an iPhone 4. While OldOS doesn’t feature all the apps that came with iOS 4, the developer plans to release the remaining apps to offer a more immersive experience.

Another great thing about OldOS is that it’s completely open source. So, you can examine its code to learn, modify, and build a similar experience in SwiftUI. If you’re interested in trying out OldOS on your iPhone, you can download it from Airport by following this link. Alternatively, you can download the app from this TestFlight link. If you wish to learn more about the project, head over to its GitHub page by following this link.