A free app for Android, by skwirrl.
You can reverse your video with the built-in reverse function and you can also make it faster or slower with a simple speed adjustment.
In order to record, you have to select the recording mode, you can choose to record with the front-facing camera or with the back-facing camera, and in order to edit, you have to select the part of the video that you want to change.
You can add a title and a description, you can also add multiple images and you can add music, you can also specify how many times the video will loop.
In order to share, you have to choose the sharing method from the menu that you want to use.