Tune your double bass instantly with precision and ease! · The most accurate - displays the exact sound frequency in Hz. · Calibration for A: 392Hz, 415Hz, 432Hz, 440Hz, 441Hz, 442Hz, 443Hz, 444Hz, 466Hz. · Instant load and fastest tuning! - Optimized for latest devices. · Highest responsiveness and sensitivity. · Intuitive user interface with LED tuning indicator. · Visual indicators - tuned string lights up. · Universal app - works with iPhone, iPad and iPod touch. · Advanced settings (A4 Calibration, Mic sensitivity, Sound notifications) and Tuning fork! (as in-app purchases) What our users say: "Does what it promises - Very useful app." "This app makes tuning so easy!" "By far the greatest and most accurate contrabass tuning app. Play the string, read its chart and you know whether you're in tune." "Amazing! Outstanding, well spent money! "All contrabassists should have this app!" "It's very useful for me! Thank you!" "Excellent app" "Very convenient software. Suitable for any skill!" --- Please make sure to allow microphone access to this app when prompted. Check it under Settings>Privacy>Microphone. Thank you. --- Got ideas? Questions? Please send us your feedback through our site or to [email protected]