'Guitar tuner' is a good accordance tool, really fast and easy in use.
You can tune standart 6 or 7 string guitar and Drop D, Drop C guitar , 4 string bass guitar or even Ukulele.
If you want to tune direct string - just
press the number of that string in application, otherwise the tuner
will automatically detect it and show you the tuning level.
Features : Tonetic generator & automatical microphon sensibility alignment
Application was tested on LG optimus
p350 and Samsung Galaxy S2.
!! iPhone Application : https://itunes.apple.com/us/app/fast-guitar-tuner/id722098191