Notation Pad - Notation Pad is the Easiest way to write sheet music with notations on iOS/Android.
Chordsheet Maker - Create chord sheets or lead sheets quick and easily from your iPad. Add rhythms, endings, segno, codas and all what's necessary for your musicians to know what's your music about. Transcription made easy!
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
Aria Maestosa - Aria Maestosa is an open-source (GPL) midi tracker/editor.
StaffPad - Write music naturally on your Windows Surface Tablet.
Tonelib JAM - Create, edit, print and listen to tablature and guitar sheet music