Hello I am naresh .i will tell you about MX player.
MX player is the best video player around the all playstore apps.
The key feature of MX player
It is very useful of watching movies, all type pf videos.it supports almost all kinds of video with all type of video formats like .mkv .mp4 .3gp etc.it has very good interface too .very simple to use and very useful for watching movies and videos etc.