this bundle zipped for download.
Once it is downloaded you'll need to unzip it. Just double click on it and follow the instructions. Once you get it unzipped so that you have the macPAF application you'll still need to deal with the fact that this is not a certified program sold through the App Store. If you just double click on it to start it you'll get an error message complaining about it being an unsafe program. It won't run the program.
But if you open a Finder window that shows the app you can do a control-click on macPAF to open the context menu. The first item in the context menu is 'Open'. Once you click on Open you'll get another pop-up that will give you the chance to run the program.
Once the program is running it shows the PAF icon in the dock. I used that opportunity to make it stay in the dock. I did a control-click on the PAF icon in the doc and chose the option that keeps it in the doc.