Google who purchased NIK software are now giving the complete software bundle of NIK add ons for Lightroom and Photoshop away for free download.
I've used their Silver Efex pro 2 in the past for B&W editing and it has some good features.
The plug ins are handy particularly for Lightroom users I think for the intuitive way it can do masking.
Probably best used for selective finishing touches when needed before export.
Even if you find one useful feature from the 7 different plug ins, then it is probably worth the 430mb download.
The current download page https://www.google.com/nikcollection/
is a bit confusing.
It describes the bundle as a 15 day trial of starters, it does not describe the plug ins by version number and it does not list Windows 10 as compatible.
I have installed them on Windows 10 and they are all the latest versions.