Guitar Pro 7 - Create, play and share your tabs
Chord NOTE - Easily find the right chords to match a melody or musical phrase.
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
Plugin Boutique - Inspirational MIDI effect that makes finding chords and progressions intuitive and fun
OpenMPT - OpenMPT is a popular tracker software for Windows.
Instachord - MIDI Processing Plugin that helps you play chords and chord progressions faster and easier.