StepperMillimeter is a free Android app developed by Nitramite under the Utilities & Tools category. It is a must-have tool for anyone who wants to make their 3D printer or CNC machine accurate. The app can calculate the needed steps per millimeter for both pulleys and belts and threaded rod or screw-driven systems.

StepperMillimeter is an essential tool that helps you fine-tune the accuracy of your 3D printer or CNC machine. With the app's initial mathematical calculation, you can adjust any kind of 3D printer from RepRap printers to CNC routers and other stepper motor-driven applications. The app also features a fine-tuning tool to make precise adjustments after the initial calculation.

Overall, StepperMillimeter is an excellent app for anyone who wants to make their 3D printer or CNC machine more accurate. It is easy to use and will save you a lot of time and effort in the long run.