Windows only: Freeware application Unhider re-displays invisible applications in the wake of a system error—like a Windows Explorer crash—after which some of your application windows remain hidden. If you've been using Windows for any amount of time, you've probably experienced a situation similar to this. Rather than begrudgingly quitting the application you're unable to access and losing the work you've done, fire up Unhider and it'll make your window visible again. It's not an app you're likely to use everyday, but you'll be glad you have it when the time comes. Unhider is freeware, Windows only.