The best video player for Abdroid plateform is Mx player,it supports almost all major video formats, You can control the playing videos through gestures such as pinch to zoom, volume ,seek time, brightness etc.It supports mkv format and other dual audio video formats. You can increase volume upto 200%. Abdroid users can watch any video format video without converting them with mx player.
The best thing that it is free on playstore and you do not need to buy full version (atleast i didnt needed)
Hope this article will help you