The main window contains a number of child windows which allow you to edit the current ECU calibration and show and datalogging and graphing.
The Status Bar (at the bottom of the main window) contains:
On Line / Off Line - Shows if the laptop is connected to the ECU via the USB cable.
Datalog - displays Datalog when the ECU is being datalogged.
Record - displays Record when the ECU is being recorded.
Modified flag - displays Modified when the calibration has been edited but not saved.