From Enable Software:
Enable Encore is a real-time instrument tuner and metronome. Enable Encore performs real-time tuning for a range of instruments, as well as providing presets for each instrument in a variety of styles. Enable Encore automatically determines your instrument/string's current frequency to high accuracy, and tells you the corresponding musical note. Enable Encore comes complete with an integrated metronome, providing a range of preset speed styles, accents, output instruments and real-time recording facilities.