I've been searching for a simple, working, free guitar tuner program, but there seems to be a gap in the free simple working tuner market on the web. So I decided to make a chromatic tuner, which works for many instruments.
To use the tuner, simply connect a microphone to your computer, and download and run the installer, and then run the program. It will estimate the current note from the recorded audio. For electric instruments, you will get the best results by directly connecting the output of your instrument to the microphone jack on your computer. The only option available is to set the middle A frequency, by default it is set to 440 Hz.
Let me know how it works for you! I've tested it with an electric guitar (directly connected and using the mic), a violin, and a piano so far. It performed well with all of them, except it sometimes struggles to identify the octave of the lowest few notes on the piano.