A4tune is an extremely accurate tuner for guitars and violins. Professionals appreciate its precision, beginners quickly learn to tune instruments properly. The app is easy to use thanks to a combination of chromatic and strobe tuners on one screen, and provides the most accurate tuning you can achieve.The chromatic and strobe tuners are independent, but both use the same input from the built-in microphone of your phone or tablet for their advanced algorithms.Chromatic tunerThe chromatic tuner precisely detects of the frequency of the tone played on your guitar or violin, and shows it on the chromatic scale. The target strings are highlighted on the scale, and you can see how far is the tone from being in tune. When you get close enough, you can use the strobe tuner for fine tuning.Strobe tunerAfter you have used the chromatic tuner to get close enough to the target frequency, you can start looking at the strobe tuner. When the pattern is moving to the right, it means the tone is too high, and you need to tune down. When it is moving to the left, just tune up. The slower the pattern moves, the better is your instrument tuned.If you are in doubt how to use the tuner, please read the built-in help, and see the examples of the tuning process there.The strobe tuner uses an independent algorithm from the chromatic tuner. While the chromatic tuner uses the Fast Fourier Transformation, the algorithm in the strobe tuner is much closer to what you can find in oscilloscopes, and is computed directly on the GPU of your phone / tablet.Tuning by earYou can also play the reference tones using the "Play Tone" buttons at the bottom of the screen. The tone is synthesized, and respects the setting of the concert pitch.GuitarThe tuner has been tested with many guitars and violins, and we constantly grow our test coverage with new recordings of the instruments. You can switch between the guitar and violin tuning in the settings.ViolinThe strobe view allows you to tune as precisely as the professional violinists tune by ear. The chromatic view helps the novice players to improve their accuracy when exercising.Other instrumentsThe chromatic tuner can be used with other instruments too, but you will have to ignore the strobe view. We also limit the range of the frequencies to what is usual on a guitar or on a violin. We will add more instruments later, when we grow our test suite with their recordings.Features:* Guitar tuner beginner & pro* Violin precision tuner* Advanced noise cancellation - works even with a metronome on* The most favorite alternate guitar tunings* Easy to use for violin and guitar beginners* Precision tuner suitable for professionals* Plays reference tones* First-start tutorial to understand the usage* Built-in help to understand the app better* Two independent tuning algorithms: chromatic tuner using the fourier transformation and strobe tuner emulating the stroboscopic effect* Quick, precise, and accurate tuner* Free, Ad-free* Possibility to donate for further development* Concert pitch frequency setting* Note naming: English, European, Solmization* Equal temperament* Quick access to settings to switch between violin and guitar tuning* Send feedback: Record the string, e-mail it directly from the application, and we will add it to our built-in tests.* Tested with many instruments, and test guitar / violin recordings are in a test suite that is regularly run before every release.A4tune is ideal for all violins and guitars, and you'll really enjoy the sound of your instrument, and the music you play!