Learning a new song? Hard intervals? Weird notes? Hard runs? The SightSing app for choral learning shows you the music, plays the notes, keeps time and even tells you if the note is correct. Start at the beginning or any measure that you want. Adjust the tempo to go slow at first, then speed it up as you learn it.
You can disable individual parts, or pan the sound so that your part is in your left ear and the other parts are in your right ear (requires headphones).
Compose or copy songs you are interested in. Type in lyrics, drag and drop notes into a staff, build multiple staffs into movements.
Share songs with friends, or share with everybody.