BookWidgets - BookWidgets is an excellent application that let you create engaging exercises in minutes and easily share a varied variety of beautiful and fun activities with your classroom and others.

yalp.io - Automatic chords extraction from mp3 and YouTube

Padlet - Visual boards for organizing anything.

ChordU - Extracts chords from any song, integrated YouTube.

Socrative - Socrative helps teachers engage the class with educational activities to measure and visualize...

Guitaa.com - Turn ANY song into chords, play along with interactive chords and diagram, transpose, loop, tempo control.