im slow but would like to share..
try using this
https://play.google.com/store/apps/details?id=com.mxtech.videoplayer.ad&feature=search_result#?t=W251bGwsMSwxLDEsImNvbS5teHRlY2gudmlkZW9wbGF5ZXIuYWQiXQ..
i think its an awesome vid player..plays all my .mkv and rmvb files..with subtitles...the user interface is awesome too..
and regarding battery life, i've got to say im disappointed at first too. but im pretty much used to it already. first off this is my FIRST smartphone..have been stucked with a noob samsung since army. so having the transition from a phone that last me for days to one that last me for less than a day is kinda big. but honestly, looking at the stuff i do with xs, i dont think its unreasonable at all. first of all, im someone who sleep for less than 5 hrs a day. so the amount of time my phone has no activity at all is really little. throughout the day i'd play games, watch some youtube or surf on it..each lasting for like 15-20 mins?..so probably 3 hrs in total..things like whatsapp, calling are pretty frequent too. i dont know how you guys would rank this frequency of usage but im guessing its at a rather normal level. the bat last me for about 18 hours?..one thing i found impressive is that after i watched 3 episodes (abt 2+hrs) of Mythbusters with 720p reso..the bat went from 85% to 41%...with a HD screen, i'd nv expect that...so for me the bat life is quite reasonable - unless you are a hardcore social media freak who has to be constantly updated with fb/tweeter/blogs+++ den i guess its never going to satisfy you. just my 2cents worth