For help with learning guitar
Yousician offers personalized lessons in guitar, bass, ukulele, piano, and now voice. Instructors demonstrate techniques in video clips, and the app listens and grades you as you play along to scrolling tab notations.
Guitar Tricks has a larger song library, plus 11,000 video lessons. You can customize a curriculum and even book private or group lessons with a live instructor. The service, available online and through an Android app, has instructional videos for 700 songs.
FourChords demystifies music by demonstrating how to play 2,000 well-known songs using just four guitar chords in each case.
Chordify analyzes any uploaded song to produce a measure-by-measure chord chart. You can then transpose the music and play it back.
Amazing Slow Downer slows down recorded music without affecting pitch—useful when you’re figuring out a tricky lick.
Source: Acoustic Guitar