Tuner app for tuning musical instruments with features like: * Detect pitch based on autocorrelation and FFT spectrum. * Accuracy improvement by evaluating the spectrum phase information and polynomial fitting. * Show how pitch changes over time. * Basic instrument database (chromatic, guitar, bass, violin, …) * Support for custom instruments * Several temperaments like equal, just, Werckmeister, Kirnberger, … * Non-12-tone temperaments (EDO 17, 19, …, 41, 53) * Scientific settings like FFT window size, FFT window type, overlap and more.