Tunr is a free and simple-to-use chromatic tuner available for Android devices. It can tune any musical string instrument by using your device's microphone to detect the pitch and intensity of the sound in real-time. It is a versatile tuner that works for guitar, bass, ukulele, violin, viola, banjo, mandolin, bouzouki, and even vocals/songs.

Tunr offers both visual and audio feedback to help you tune your instrument. The tuning signal history shows the pitch of the string being played, and the manual mode allows you to tune by ear. You can also redefine the concert A4 target frequency from 440 Hz to your desired frequency. Tunr has notes in several languages and systems, such as Solfege, East European, Indian, and Japanese.

Whether you're a beginner or an advanced player, Tunr is simple and intuitive to use. It comes with presets for standard and alternate tunings, such as drop D tuning and full step down tuning for the guitar. With Tunr, you get accurate tuning results, making it an essential tool for any musician.