If you use Photoshop at all, you most likely have your own custom set of plug-ins and filters to help with your photo and image editing. And most likely you've heard of Nik, Google's amazing photo editing tool that works with Photoshop to give you an edge on advanced editing. It was $150 for the collection of all seven desktop plug-ins. Now, it's completely free.
"Starting March 24, 2016, the latest Nik Collection will be freely available to download: Analog Efex Pro, Color Efex Pro, Silver Efex Pro, Viveza, HDR Efex Pro, Sharpener Pro and Dfine."
This is an extremely handy tool to have in your pipeline, whether you need to prep textures, modify backplates, enhance HDRIs, or use it in post. It's on our team's list of must have tools, worth the previous price, but oh so much sweeter now that it's free.