Jokosher - Jokosher is a simple and powerful multi-track studio.
Stave'n'Tabs - iOS and macOS notation and tablature editor with MIDI and MusicXML files support and chromatic...
Fission - Edit audio in minutes, not hours.
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!
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
Aria Maestosa - Aria Maestosa is an open-source (GPL) midi tracker/editor.