This document provides a tutorial for using Ranorex to test the GUI of a SimpleCalculator application. It discusses: 1. Installing and setting up Ranorex, which allows simulating user interactions for GUI testing. 2. Adding a GUITester class to an existing SimpleCalculator project and referencing the Ranorex library. 3. Writing tests that use Ranorex methods to control the mouse, interact with calculator controls, and assert the result is correct. 4. Running the GUI tests using the NUnit test runner to automatically simulate user interactions and verify functionality.