I did, sometimes. When it works, it works great, but often it doesn't. There are also Matcherator[1] and What Font is[2], but they are not better or worse in my admittedly limited experience.
Personally, I've had much more luck with the manual font identifying tools which ask you specific questions about the letters you have. Mostly because often the font I'm looking for is on an image with a lot of noise and these automatic systems have a hard time isolating the letter.
http://www.identifont.com/
https://www.fonts.com/id/by-sight