Whether you've never written a note onto staves (cough. that's me) or you're well-versed in verses, this app might be just what you need to make the notation process a whole lot faster and easier.
Komp, from developers Semitone Audio, aims to convert your quick sketches on an iPad into actual notes and offers a load of features just not possible with pen & paper.
As well as quickly correcting or erasing notes, you can play back a phrase, select and edit whole groups of notes, add dynamics and articulations, and them export your piece as an XML file.
There's a free version and a $5 per month subscription model that adds a load more functionality.
Komp hasn't launched yet, but should be coming very soon.