Unfortunately due to all my other commitments, I haven't been able to maintain the code for the pitching rate calculator. There were some people that produced iPhone and Android apps for the calculator. They were supposed to pass along a portion of the proceeds to me (and some did initially), but I haven't been paid for them or have any control over what they put out curently. Sorry about that. When I get the time (or if someone else wants to help out) I will get a calculator going again on this page.
The Mr Malty calculator was the very first pitching rate calculator. Soon many others copied the Mr Malty app, but this was the first and was based on actual brewing and lab data. Hopefully it will live again in the not too distant future.