As for me, (due to time constraint) this would come up:
1. Recitation
2. maybe add an option to read out loud the translation with espeak
3. Auto scroll mode. (not that important though)

I think a big feature with the releated features would be good to concentrate on.

I would like to make a request.. i.e about recitation ( 1. full surah recitation, 2. page recitation, 3.verse recitation,) p.s. same applies to translation recitation.