Just use YAT, the simplest chromatic tuner app, to visual tune instruments and voices using the built-in mic in your mobile device.Also includes a function to play an audible "A" as reference for tuning by ear.You can configure the desired frequency of the "A" or can play (or sing) it and YAT will adopt it as the "A" frequency.Select the ruler to savarts (default), cents o commas.Choose how many semitones to show on screen.You can download and enjoy it for free or buy to unlock premium functions.Additional functions:Play the defined "A" Get the "A" that you play in your instrument. (*) Increase the frequency of the "A". (*) Decrease the frequency of the "A". (*) Reset "A" with the "Initial" frequency defined in Preferences. (*) Preferences, define YAT parameters. (*) Help. (*) Premium function