A free app for Android, by Photo Slideshow with Music.
This is a simple and easy-to-use app that can merge multiple video files into one. You can easily select the video files you want to merge and also select the output format of the resulting video file. Once you’ve made your selection, click on the “Start” button and the process will begin. You will be able to view the progress of the process at any time. Once the process is complete, you will be able to download the resulting video file.
This app supports different formats and different frame rates, frame sizes, and audio rates. You will be able to choose the frame rate you want (from 0 to 4.0 seconds per second) and also the frame size (in pixels).