7 Tuner!

Finally a iPhone tuner that works - User Review7 Tuner is a professional guitar tuner using a new sophisticated two-step interpolating algorithm to guarantee maximum tuning precision of about 1 cent. 7 Tuner can tune your acoustic or your electric guitars. Note: if 7 Tuner does not seem to work correctly, check if you have selected the correct pitch (usually 440.0 Hz).7 Tuner uses guitar harmonics to get maximum tuning precision - no other instruments are supported yet.