Multiple monitor support
It would be great for Freeter to support multiple monitors. This could be by spanning multiple monitors 'cleverly', so that widgets etc. don't end up spanning multiple screen borders (this could be done manually of course); or even better by allowing Freeter to have multiple windows (all from the same app), similar to how Visual Studio or IntelliJ IDEA or Photoshop or Illustrator have floating windows/toolbars.
Ideally the layouts would be remembered on a per-monitor configuration basis.