Looks like the nice folks at Skylum (formerly Macphun Software) have made three of their apps free for macOS users.
Intensify “helps you create sharp, crisp and dramatic photos in 1 click.”
ColorStrokes lets you “pick a part of the image to leave in color and the rest of the photo will turn monochrome”.
My personal favourite of the three is Snapheal which often does a surprisingly good job of removing “unwanted objects & people from photos in 1 click”.
“Please note: this is a legacy product; the current version is the last one.”
Use ’em while they last, folks. Guess they’re adding the functionality to other apps?
Any product that promises to instantly fix photos in one click…
…doesn’t.