Nic software's Color Efex Pro, Silver Efex Pro, Sharpener Pro & Viveza are fairly famous in photography enthusiasts though the bundled cost was $500, still photographer's world wide were using it legally or illegally . In September 2012 Google acquired Nic Softwares and in 2013 they started selling the wonderful Nik Suit for the low price of $150.
AND NOW IT's FREE- Yes absolutely Free!
As per the Google's Official announcement the Complete collection is available to download absolutely Free
"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.
Not only this, if you have purchased the Nik collection recently, you can claim for a complete refund...
"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. If you purchased the Nik Collection in 2016, you will receive a full refund, which we’ll automatically issue back to you in the coming days."
So folks download this incredible collection of plugins now to make your images look wonderfully beautiful.