FIPLAB Ltd has Converto – The Unit Converter in the Mac App Store for FREE (regularly $1.99) for a limited time. Deal expires April 28, 2013.

Converto is the best unit converter for your Mac. It makes changing between various units quick and easy. The app lives in your Mac’s menubar and is always available at the click of a button. Instantly convert numbers into dozens of different types of units – anything from mass, energy, currencies, temperature, volume, length and much more.