From Bernhard Stopper :
Exclusively featuring StopperStimmung (1988), a slightly stretched tuning creating an amazing and clear sound on your instrument by the tunings recently discovered (2004) stunning structural symmetry. The temperament compromise is strongly lessened by symmetrically interfering harmonics making chords to appear as being pure tuned.
The essential of a tuner is tuning quality, not features. Choose your appropriate tuner out of three available guitar versions, to suit your specific needs.