ChordIQ - Learn notes, chords, sight reading, perfect pitch and more.
Guitar Pro 7 - Create, play and share your tabs
soundrop - Soundrop is an app that allows you to create your own personalized sound track to keep you focused or relax.
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
muted.io - A magical collection of interactive music theory tools & visual reference pages for musicians and music producers
OpenMPT - OpenMPT is a popular tracker software for Windows.