If the window appears cut off or you are unable to find the resize widget go to the Window menu at the top of your screen and select 'Zoom'. This will resize your window so it fits within your screen's dimensions.
You can also go to the Window menu and select 'Bring All To Front' which will gather all windows on your main screen. This can help if a window is completely off screen, for example if you previously opened EverWeb on an external monitor.