A recent AVG and Avast antivirus update is preventing DisplayFusion 9.9 from launching on some systems.
If you're running into this issue, please update to the latest DisplayFusion 10.0 Beta.

DisplayFusion's Window Snapping feature makes it easy to line-up your windows with each other, or line-up your windows along a monitor edge. Just drag a window near a monitor edge or another window and release the mouse button to let DisplayFusion snap the window into place. Fully configurable, with the ability to ignore specific applications if needed.

The Window Snapping feature is fully configurable, allowing you to specify the snap distance before a window snaps. You can also assign a modifier key that you can use to override the window snap while the key is held down.