RER MKV Converter 

This program is designed to let you convert video files from MKV to different formats, such as AVI, MPEG, MP4, 3GP, FLV, WMV, MOV, VOB, TS and MP3. In terms of format support, we could say that this app isn't really all that versatile. It also lacks a lot in other key areas.

For starters, I was unable to successfully convert a single MKV file with this application. I tried with three different files stored in MKV containers. The video formats were H.264 and MPEG-4, which are very popular these days and most video players can open them. The files loaded fine, but after conversion they all displayed the same error. When I opened the files with VLC, there was red text on black background which read "DirectShowSource: Could not open as video or audio". And some other, more technical errors. I tried converting to MP4 and MOV, to no avail. This leads me to believe that the application hasn't been updated for a while.

Another area where this app fails is design. It has probably the worst graphical user interface that I have ever seen. Also, even if it worked flawlessly, $24 is a high price for a single-format converter that has no video editing features, profiles or GPU acceleration.