Guitar Pro 7 - Create, play and share your tabs
Flowkey - The easiest way to learn piano with your iPhone or iPad
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
Yousician - Learn to play music at home, at your own pace
OpenMPT - OpenMPT is a popular tracker software for Windows.
Melodics - Melodics is a desktop app that teaches you to play MIDI keyboards, pad controllers, and drums.