According to some code discovered by XDA on the most recent version of the YouTube mobile app (version 11.20.54), some of the filters used to search on the desktop version of YouTube will be coming to the mobile version of the video streamer. The strings discovered by XDA point to the ability of the mobile YouTube app user to be able to search for videos by rating, relevance and view count.
These filters have yet to show up in the mobile app.
