Nyrna - a Linux/Windows tool to suspend/resume games and applications

This doesn't do anything particularly revolutionary, but it does give you a nice GUI with the ability to assign hotkeys to suspend/resume.

Useful if you want console-like game suspend to quick-switch between games, or if you're just trying to save on the electricity bill.

EDIT to add: suspended apps stay in RAM/VRAM, so be aware of your specs/game requirements if you're trying to achieve console-like "game switching". Also, could be incredibly useful for mobile gamers to save on battery/cool down the device a bit while not playing for a minute or two.