UR SIM is described as 'With this software installed it is possible to create and run programs on a simulated robot, with some limitations. The most important of these limitations is that it is not possible to simulate digital/analogue input to the robot' and is an app. There are six alternatives to UR SIM for Windows, Linux, Mac, Web-based and Raspberry Pi OS. The best UR SIM alternative is Throbol, which is both free and Open Source. Other great apps like UR SIM are RoboDK Professional, RobotStudio, ROBOGUIDE and K-ROSET Off Line Software.