We recently featured free engineering apps for the iPhone. One of the apps was iMachinist 1.1.3. The developer touted it as “community driven machining/engineering calculator.” The idea: if you don't see an equation you want, just email the developer and he will add it. Evidently, this is not exactly true. A reader recently wrote in, saying, "I have had the app for over 6 months if not more. It has an annoying bug in that the period key doesn't come up on the first occurrence of entering values in some circumstances. I e-mailed the author and he responded that he would fix the bug in a few weeks. That was over 6 months ago. I consider the author non responsive and suggest that one look for other apps."