Android app- transpose to a new key- great differentiator to drive adoption
The ability to transpose a song into a different key on in the tablet app would be a killer.
IMHO, as simply a sheet music viewer/player, MuseScore on a tablet is kinda useful, but is frankly in a crowded field.
But if you could bring the tablet with MuseScore to a jam with your library of songs on it in mcsz format, and be able to transpose them right there, on-the-fly as songs are called, into whatever key they are called in ... well that would be a huge value and huge differentiator from the many other "sheet music library" apps.
In particular, I believe MuseScore has a big challenge trying to gain adoption in competition with ForScore (apple) and MobileSheets (Android) as a sheet music reader/library. Both of those apps have wide penetration and use already. They get very high ratings in the stores, and are richly developed, and frankly work very well. MuseScore can PLAY the tune as it's written. But ForeScore and MobileSheets can link and play MP3's. That's different than playing the score as written --- sometimes the mp3 will be better, sometimes the score will be better. But it doesn't give MuseScore a clear winner advantage.
Transposing is a frequent need, and neither of them can transpose, and because they are image-based (PDF, png, etc) -- it would be a huge re-write for them to add the ability to transpose.
On the other hand, MuseScore has an ideal architecture for transposing, using a notation-based file. To me, it appears to be a terrific value proposition, and a very logical+ effective way to differentiate MuseScore and gain adoption.