This is the ad supported version of Tuner - gStrings, a chromatic tuner application measuring sound pitch and intensity.
It will let you tune any musical instrument (violin, viola, violoncello, bass, guitar, piano, wind instruments).
1. orchestra tuning (shifting/redefining tone frequencies),
2. different temperaments (just, pythagorean, meantone, comma, etc.),
3. a variable range nonlinear scale,
4. microphone sensitivity setup,
5. pitch pipe,
and many more.
If you were looking for a guitar tuner, try it!