What ipad music reader are you using?
Do you like it?

I am looking for the perfect ipad music reader.... Which means it should be able to

1) read pdf music sheets
2) play the music sheet to give an indication of the sound
3) has online store from which to buy new sheet music
4) allows me to share sheetmusic with friends
5) convert a picture i take with my ipad from my paper music sheets into a readable pdf sheet music
6) allows me to make notations on the sheets..
7) be controlled over midi for page changes
8) handle both sheetmusic as leadsheets as chordsheets
Did i forget any important features you deem unmissable in a sheetmusic reader?

Anyone got any suggestions?
There are so many available in the itunes store, it would take me ages to figure out which is best...