Convert your Xcode project from iPhone to Universal, and update AppIcon accordingly

I started my application for iPhone only, then I learned about size classes and decided that it’s not feasible to implement an universal App. All you have to do is go to your TARGETS in the Xcode and change Devices to Universal. This is all easy and simple, but it got tricky when I went back to AppIcon. It didn’t add icons for iPad devices. I tried a lot of things, and one of the easy fixes was to create a new Xcode project with Devices set to Universal, go to its AppIcon and drag that to your project. I know this is not very smart , but it could save you a lot of time if you have no other easy fix.