AquaSnap - Too many windows on your screen? Stop wasting your productivity.

Dropzone - If you want your file uploads to work even without JavaScript, you can include an element with the class fallback that dropzone will remove if the browser is supported.

Mizage Divvy - Divvy is an entirely new way of managing your workspace.

Dropover - Mac app for easier drag & drop

Moom - Move your mouse over the green zoom button in any window, and Moom's mouse control overlay will appear (as seen in the above animation).

Unclutter - Unclutter is an app that is designed to help Mac users bring order to their desktop. Among other features, this powerful piece of software provides quick access to a user's notepad and clipboard.