MP4 Player is designed for users who want to play MP4 and FLV videos downloaded from YouTube on their PC. MP4 Player is a handy windows app, and its installer file size is only 645KB. The portable version is much smaller - 267KB. How To Use MP4 Player: Simply drag the MP4 or FLV videos onto the player, it will start playing immediately. You can find the portable version and installer version both on the site url http://www.mp4tomp3converter.net/mp4player.html