Windows: Glary Utilities is a comprehensive PC maintenance tool that cleans and repairs your system, optimises startup and memory, and shreds and undeletes files. The Pro edition, normally $US40 (discounted to $US28 right now) is completely free with this special promo.
The Pro edition promises enhanced system fixing and optimising, automatic maintenance in the background, free technical support and allows for commercial use.
To get it, download the "Slim Build" from the link below. Then after installing Glary Utilities, go to the Status tab and click to register with this information:
Registration Name: EaseUS Users Registration Code: 3788-61679-58234-2362
The promotion is offered by EaseUS and shared by Slickdeals user acr.
There's no word on how long this promo will last, so if you're looking for a free upgraded swiss-army-knife type of system optimiser, head over to the download page sooner rather than later.