The app claims support for HEVC/h265, but its not working quite right for me. And unfortunately the App Support link leads to a non-english webpage and there is no in-app help or contact info.The problem is, when I remux an MKV file with HEVC-encoded video to MP4, the video won't play in some apps. VLC is OK, but neither Quicktime nor Quick Look will play it. When I use a different app to remux the same video, it works everywhere as expected. I compared the working video to the video created by this app, and the only obvious difference is the "Codec ID" on the video stream, which in the working video is "hvc1" whereas this app set it as "hev1". As a test, I opened the non-working video in a hex editor and changed "hev1" to "hvc1" near the end of the file, and then it worked as expected.For what its worth the h264 videos I used worked fine in this app, and it works well for the most part and is easy to use. But at the end of the day its just a simple FFmpeg wrapper with poor HEVC support.

There is a review from two years ago that says it does not remux HEVC/H.265 properly, but that has been patched and it works now. Importantly, it allows you to keep all of your audio tracks in tact as well, which is very important for me.