Do not buy this app unless you are a professional piano technician. This is a professional tool that produces a custom piano tuning for any piano. It is part of our popular TuneLab line of piano tuning programs for Smartphones, tablet computers, and laptops, which piano technicians have been using for more than 15 years. Notable features: * Capable of an accuracy of 0.02 cents. * Measures and uses inharmonicity of the piano to construct the tuning. * Provides an over-pull mode for more accurate pitch-raises. * Can store hundreds of tuning files for individual pianos. * Tuning files can be stored locally and in the Cloud on Dropbox. * Provides many historical temperaments for period music. * Switches notes automatically when you play the next note. * Provides a strobe-like Phase Display for fine-tuning. * Provides a versatile frequency spectrum display. TuneLab lets you customize a tuning by sampling the inharmonicity for a few notes of the particular piano. You can choose the kind of tuning stretch you want, based on octaves, double-octaves, or other intervals. Then you start tuning. After a custom tuning has been created from inharmonicity measurements you can store this tuning by name. The next time you need to tune that piano, or one very much like it, you simply load that same tuning file and start tuning. There is essentially no limit to the number of tuning files that you can save. TuneLab comes with some sample tuning files and an "Average" tuning file so you can start tuning right away without bothering to measure inharmonicity. TuneLab covers the normal piano range from A0 to C8 (88 notes). The automatic note-switching feature makes it possible to enjoy hands-free operation. TuneLab switches up to 3 notes up or down from the current note. There is also easy one-touch manual note switching. TuneLab has two different displays that are visible at the same time. One is the 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 in the frequency spectrum for every pitch present in the sound. You tune to make a peak in the graph move to a central red line. The spectrum display makes it possible to do rough tuning without mutes, since each string of a unison produces its own peak in the graph. Having both the Phase Display and the Spectrum Display visible at the same time gives you a more complete picture of the tuning than any single spinner-type or needle-type display.