Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.

Fretello - Duolingo for learning how to play guitar

Airborn - Create and edit documents online without sacrificing your privacy

Justin Guitar - Over 750 completely free guitar lessons!

Bit.ai - Bit is a smart real-time document collaboration platform for teams to create interactive documents, manage digital content and track document insights.

Uberchord Guitar - Get better on your guitar. Fast.