Fretello - Duolingo for learning how to play guitar
Guitar Pro 7 - Create, play and share your tabs
Justin Guitar - Over 750 completely free guitar lessons!
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
Uberchord Guitar - Get better on your guitar. Fast.
OpenMPT - OpenMPT is a popular tracker software for Windows.