To download a video, first select "Playback" and then click on the download symbol. You can adjust the length of the clip before downloading the file.
When the video has been downloaded you can find it either;
1. In your internal storage via a file manager app e.g. "FIle manager (No ads)" (Android only) On iPhone the download is found in the photo album.
2. You can select where to send the file.
Alternatively you can remove the SD card from the camera and read it with a computer.