STITCH

herramienta sencilla para ver dos videos de lado a lado, y guardarlo como un tercer video.

This app allows you to see two videos side by side. For example, it can be used compare the difference in ride quality between two motorcycles ridden over the same patch of road. All you have to do is switch on your camera and record your ride on both bikes. Then use STITCH to put the two videos next to each other and view them side-by-side. What's more, you can save the output video too, and transfer it between devices (e.g. phone to laptop).