Good DLNA client with potential for improvement

I tested on the Fire TV Stick the VIMU Player. Most films (mkv, mp4, avi) were for the most part (for now!) Played without sound. When you play a particular file, a message came on the screen that the audio codec is unknown and one should activate the new VIMU Media Engine in the advanced settings of the app. This is what I made and (drum roll ...) almost all video and audio is now available! Only DTS sound currently does not work yet (License gray area?). Here you have necessary back up the soundtrack itself on the PC to convert ac3. With the new media engine, however I had problems to play some MP3 files. Although there was no error, but the "charging circuit" not disappeared and I had with "Back" back to the menu. With the old media engine these MP3's but was then loaded easily. The new media engine to support various audio tracks and subtitles, but there are currently no menu where you can select this. So with a little development work could be a really useful Movie streaming app for the Fire this TV Media Player / DLNA client.