pluto

we have a video file, with a video/ mime type, however, it does not get played by the embedded video player.
the app asks to search Google Play for apps that can play that video mime type. this is not great[*]

so, we have this situation: if we rename the file's extension to .mp4, it plays just fine.

*from early on, we always were clear that we should default sanely for video files so that we do not have to explicitly whitelist new types and make a new release like we have now.