Screen recordings flicker and jitter in After Effects

Using a screenrecording from either an iPhone or XCode Simulator in Adobe After Effects might give you not the results you are looking for. The framerate jumps to various rates and when rendering the video in Adobe Media Encoder you might have a video that jitters and flickers like never seen before.
To make the footage usable in After Effects you have to render the original footage via Finder on macOS. To do that open Finder and right click on your file, go to Services › Encode Selected Video Files. There you select Apple ProRes in the settings and click on Continue. After some seconds/minutes you have a way bigger but perfect file that you can work with in After Effects.