Does what it says. Pro Version gets you Fan control

Although updating it to the latest version (and also to Pro for another $5) is an annoying hassle; I that’s more Apple’s fault than the developers. I think it digs a little further into the OS’ hardware functions than Apple is comfortable with.
The external installation is a bit quirky but Tunabelly’s support was very quick (a couple of hours for me) and accurate.
The app itself works better than I expected, flawlessly in fact.

Matt Sahlgren about Temperature Gauge