If prompted, allow the app to "Read User Data" so it can access the videos stored on your memory card. For Developers: MP4 Playback Libraries
If you are using a classic Java-enabled phone, these are the most reliable video players available in JAR format: download mp4 video player jar
A Java-adapted version of the popular desktop player that supports MP4, 3GP, and ASF files. If prompted, allow the app to "Read User