I'm very fond of the Luminar software. It's not free, I got an earlier version through a Humble Bundles deal (they have some amazing fully licensed software bundles, books, educational packages (mostly IT related), games and other stuff), all legal and cheap.
https://www.humblebundle.com/
My son got Luminar Neo, I didn't, I run Windows 7 on my primary system and it requires Windows 10 minimum.
I also use a program called Aurora HDR, possibly in the same image processing bundle, it's very good too.