'Save to filesystem' - Too technical, needs to be something like 'Save to file'
Add keyboard shortcuts for items in Document menu
Window Size - The window size is too small by default, needs to be larger
The frame in which the preview is situated needs to have a border
Use icons for the + & - symbols beside the zoom slider
The window title should be the same as the menu item name (ie. Simple Scan)
Is there a need for the Save and Print button to be in the menu and in the content area?