Recenser is an easy-to-use video editor that can make your videos look even better. It can also remove unwanted elements, like the green screen, and add new elements, like the audio and the image. You can also increase a video's framerate using the app's built-in motion smoothing funciton.

It's very easy to use and has a simple user interface, so you don't need to spend much time learning how to use it. It's just a few MB in size and it's fast, so you don't need to worry about it slowing down your phone.