So one thing about Android is that the default video player has a good interface but can not play HD videos such as mkv,etc. So if you are a of fan of movies in HD a must have app is the MX Player available on the Play Store for free. With a nice clean interface, useful settings, variety of formats and minimal ads it is the ideal app to watch movies. It is also a music player. If you are like us and find Play Music insufficient in terms of features, you may like this app. So download now for free from the Play Store.