At first you simply easily specify by moving and resizing an area the source magnification area and press the "OK" button. Afterwards, you specify the destination magnification area and press the "OK" button.
Then the source area you specified will get zoomed and will be shown on the magnification window.
You can also specify that the magnification area follows the mouse cursor movement.
By pressing Control - F9 you can specify the source and destination magnification areas again and by pressing the Escape key you exit the application.
When the application is first started it asks you for your desired user interface language.
You can also change the user interface language from the "Language" menu.