The Video app is a simple video player that allows you to play any videos stored on your Firefox OS device's storage media.
By default when you open the Video app you'll get a message saying that there are no videos available to play, and that you'll need to add some videos. This can be done either using the Camera app to record videos, or by mounting the device's storage as a drive on a computer and copying the files over. There are two buttons at the bottom of the app: the left hand one takes you to the Camera app to record more videos or take pictures, and the right hand one takes you to the gallery where you can view videos or pictures.
To copy the files over using a computer, make sure “Enable USB Storage” is enabled (Settings > Media Storage > Enable USB Storage). If a “Videos” directory does not already exist, create one, using that exact name.
You can change whrere the videos are stored by changing the Default media location (inside Settings > Media Storage) between “SD Card” and "Internal".
Note: If you are having trouble getting video to play on Firefox OS, you should be aware of two things. First of all, some versions of Firefox OS ignore video files if they are too big - this should be fixed in a future version. Second, Firefox OS will play most of the common video formats available, but not all. You can check with ones on our Supported Media Formats article.