Nik Collection for free.
If you are still don’t know, Google provides a free collection of plug-ins from the Nik Collection. It includes Analog Efex Pro, Color Efex Pro, Silver Efex Pro, Viveza, HDR Efex Pro, Sharpener Pro and Dfine.
It’s time to download until they change their mind.
https://www.google.com/nikcollection/
By the way, if you want to know how to level up your retouching (doesn’t matter with photoshop plugins or without), just check out my blog post about it.