I mainly used it to steer a robot. I used one Arduino on the PC, and one on the robot.
The one on the PC acted as controller for the NRF. At the same time I can unhook the controller on the PC and can use physical control (joystick, buttons) to control the robot.
The communication was manly based on predefined message patterns. Like D:100 is: go forward 100cm. For the manual/physical control it's then a simple F: to go forward until the stop message arrives.