Google:

Photo enthusiasts all over the world use the Nik Collection to get the best out of their images every day. As we continue to focus our long-term investments in building incredible photo editing tools for mobile, including Google Photos and Snapseed, we’ve decided to make the Nik Collection desktop suite available for free, so that now anyone can use it.

The Nik Collection is comprised of seven desktop plug-ins that provide a powerful range of photo editing capabilities — from filter applications that improve color correction, to retouching and creative effects, to image sharpening that brings out all the hidden details, to the ability to make adjustments to the color and tonality of images.

I’ve used these plug-ins in the past and they are very good. At the low, low price of free, they are even better. You can download them here.