Guitar Helper should help you to tune your guitar correctly.

Author notes for this release:

Hey guys! Well, i’m back with another release of my guitar assisting application. Its only been one week, but i’ve had a little time to work on it, and now its version .5 BETA, this means more content and less bugs! Installations in the README so please READ IT! Now i’ve pretty much completed all my goals for the .5 series of this application, the next release will be a week or two off, unfortunately i couldn’t implement the Guitar Pro player or the Metronome yet, but the extra scales and Flexible tuner will come in real handy.

http://forums.qj.net/f-psp-development-forum-11/t-release-guitar-helper-5b-103272.html