In split screen mode, you see video from all selected cameras on the screen at the same time
FiLMiC, which showed multi-camera video in its FiLMiC Pro application during the presentation of the iPhone 11, decided to release this feature as a free application. It can be downloaded under the name DoubleTake for free on the App Store. The app was rated 4.5 / 5.
DoubleTake allows you to shoot video simultaneously from all cameras on your iPhone. If you have an iPhone 11 Pro, it means that you can record simultaneously on four cameras, including one front.
The user interface is pretty simple. In the lower left corner of the screen you can choose how many cameras you want to activate. In the upper right corner you can select a split screen or picture in picture (PiP).
In split screen mode, you see video from all selected cameras on the screen at the same time. In PiP mode, you see video from the main camera in the background and one additional camera in the foreground inside the window, which can be moved anywhere. Finally, discrete mode saves separate files for each active camera, so you get files from each camera instead of one merged file.

Currently, the application is limited to recording resolutions up to 1080p at a speed of 24, 25 or 30 frames per second. The app is only compatible with iPhone 2019 and 2018