Think I posted here 5 weeks ago when we launched
http://www.countmycrypto.com, our calculator app which converts your crypto holdings and tracks them using local storage.
Probably worth pointing out that we've had a couple of major releases since then which have stabilised the mobile version, added a ticker and other functionality.
Our v4 release this week adds a whole load of new fiat currencies plus other functionality including a Chrome extension, and we are hoping to add more altcoins to the selection soon once we reduce our dependency on the Cryptsy API.
Please check us out if you haven't already - we're 100% free and you don't need to register