I use Awesome Bump, which is quite fantastic... and free! Problem is, to get it working on mac, you have to build it from source, I haven't tried it myself but peolple say it's working.
Here's the files
https://github.com/kmkolasinski/AwesomeBump
Here detailed instructions on how to build it
https://github.com/kmkolasinski/AwesomeBump/releases/download/BuildingAB/BuildingInstruction.pdf