RubikTimer

RubikTimer is a timer especially made for blindfold cubing. It's easy to use, and has lots of options.

The main feature: it allows you to listen to the essential timing marks while you are solving. That way during a BLD solve you will instantly know if you're going to hit that record time.
RubikTimer has a very intuitive and smart user interface. It resizes the font when you resize the window, making it useful as a background for your video's as well.