The fastest way to manage your Mac's windows in Mission Control, with keyboard navigation, shortcuts and more. It's especially useful for Macs with small displays, an excellent alternative to nervously ⌘+Tab'ing your way to declutter your windows.
I have not tried this on newer Macs, but my Mac Pro 2010 with 128GB of RAM greatly benefits from this app as I keep swafts of open windows on that machine at all times. Sometimes the amount of windows gets out of hand and going about closing them without this app would take eternity and a day.