At the shop I work at, we've started making all kinds of keyways and I haven't found an app that does everything I'd like which are: - Calculate the dimension for programming the depth of the keyseats. - Calculate the dimension for measurement of the keyseats. - Show the tolerances based on ANSI/ASME B17.1-1967 (R2013) standards. So I made it myself. I've made my best efforts to make the interface as clear and intuitive as possible, and the app as lightweight and fast as I could. You could probably run this on your digital micrometer if it had a touch screen. I decided to make it completely free and without any ads. I made the app primarily for my coworkers and myself. I'm sending it to the store in case someone else might also need it. So if you download it and it saves you time, I'm happy I could help you out :) Please let me know if you want me to add more features like metric keys, woodruffs, taper and rectangular keys etc... I'm open to expanding the app based on the needs of fellow machinists.