Piano Tuner(Pro Edition‪)‬ 4+‎

This is the world's first piano tuner that can accurately and stably detect the full-range 88-key pitch deviation.
The app can store up to 100 thousand(*) piano and contact settings, so that you can gradually accumulate customers and provide long-term services for them. You can back up all piano and contact information to iCloud to prevent loss.
If no in-app purchase, the limitation is that you can only tune all C keys, but you can use almost all of other functions to fully experience the app.

Features:
More than 0.1 cents measurement accuracy.
The “Full Range” mode can reliably recognize the full range pitch of the piano and simplify the operation. The “±6 Semitone” mode is relatively faster and has better anti-interference ability, can adapt to the sound quality is not good and the noise environment. The “None” mode has the strongest anti-interference ability and the fastest response speed.
The tuning curve can be automatically estimated with just a few keys detected.
Over-pull tuning can save much time.
The innovative Unisons tuning mode can further help piano tuning.
It is more direct and accurate to display the deviation value by numerical figure. This makes there no need to keep a close eye on the display screen when a piano key is struck, and the app will keep to display the detecting result after the end of the tone.
Detection is fast and reliable. When detecting bass tone, it is only about 3/4 seconds to start showing the results. The treble tone even if the time is very short, can be accurately detected.
Can indicate whether there is a significant beat interference.
Value and harmonic of the tuning curve can be edited.
Up to 2000(*) piano settings can be stored. Each piano setup includes the piano brand, model, number, year of manufacture, geographic location, and final tuning time, including name and telephone number of the contact, including tuning curves and standard audio frequencies. You can use the stored geographic location to call the map software navigation, use the stored phone number to make calls or send text messages. Each piano can have up to 4 tuning curves.
Only built-in microphone supported.

* Only 100 pianos can be saved when not in-app purchased.