This app is only for professional pipe organ builders and technicians. It addresses the special tuning needs of building and maintaining pipe organs. Notable features: * Covers the note range of C0 (32' pipe) to C9 (1/16' pipe) * Handles mutation ranks (Quint, etc.) and Celeste ranks * Built-in compensation to track temperature changes * Calculates pipe cutoff for trimming new pipes to length * Optional connection to Bluetooth temperature sensor * Precision strobe-like display for very precise tuning * Can be calibrated to an accuracy of 0.02 cents * Provides many historical temperaments for period music (See our support web page for a complete list.) * Switches notes automatically up to 4 notes away * Provides a versatile display of the frequency spectrum Organ Tuner has two different displays that are visible at once. One is the strobe-like Phase Display. This is a band where black squares move left or right. You tune to make the squares stop moving. The other is a Spectrum Display. This is a graph that shows a peak for every pitch present in the sound. You tune to make a peak in the graph move to a central red line. Having both the Phase Display and the Spectrum Display visible at once gives you a more complete picture of the tuning than any single spinner-type or needle-type display. A detailed user's manual is available at our support web page. You should download and read this manual before buying this app.