[pdkl95]

While it hasn't been updated in a while (get ready for OSS and JACK support only (use jack)) and the website has a few missing images, it's hard to beat baudline for frequency analysis.

http://www.baudline.com/what_is_baudline.html

[robhack]

I’m on Windows so I can’t test this one, but seeing from the screenshots, it does not seem to be aimed at musical notes and musicians.

I don't aim to be the best at frequency analysis. My goal is to help beginner musicians to get more confidence about their pitch accuracy.