I can't speak highly enough about the Precision Music Tuner. When I ordered it, I really didn't know how cool it was. My daughter is learning to play the guitar. Tuning it is the first necessary thing to do before playing anything that sounds remotely good. The Precision Music Tuner makes that so easy for her to do. Clipping it onto an area of her guitar, she can turn it on, set it to guitar mode, stroke a note and the Precision Music Tuner will tell her the note played as well as if the note is sharp, flat or on key by showing a colored gauge. The video below shows her using the Precision Music Tuner. 

Try it -Like it was provided this item in order to provide an honest review. All opinions are my own.