Simple Mandolin Tuner

Really a must-have: this chromatic mandolin tuner is very fast, accurate and recognizes all strings using the built-in mic! Easy and perfect fine-tuning for standard mandolins.
This app is developed by a musician and electrical engineer, thus it combines high usability and cutting-edge signal processing.
Simple Mandolin Tuner is easy to use and provides an aesthetic user interface.
Simple Mandolin Tuner is configured also for the iPhone X.
Features:
+ Default mandolin: G3-D4-A4-E5 tuning
+ Tone accuracy: +/- 1.0 cents
+ Large frequency range (22 Hz to 1000 Hz).
+ Gauge view of the detected tone (semitone) and octave.
+ Tuning by ear.
+ Free user support.
+ Developed for the iPhone and iPad.
In-App-Purchase:
+ Unlimited duration of reference tone for each string (aiff-sound played in a loop)
+ String Protection: warning when tuning is out of range (prevents over-tightening of mandolin strings)
+ Calibration: 430 – 500 Hz (0.1 Hz-steps)
+ Sensitivity: choose between 5 different values (from very low to very high)
+ Display of exact frequency (in Hz).
+ Spectral view of the input signal (FFT – visualization of overtones).
+ Time-domain view of the input signal (autocorrelation).

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In the case that you experience crashes (or other inconveniences) with this app, please contact me (before you give a low rating to this app) - you may use the following contact form:
http://www.simpleukuleletuner.com/support.html
where you can describe the issue.
Thanks in advance!