There was one big issue with it though. With the past years' Java updates the out of the box advanced autorouting capability (Freerouting) stopped working from within the KiCAD package. On the top of this the java files have vanished from the website, too. These are suggested by other workarounds on the net. Sad news, however there's a way to get around this. The source code has been published on git.
With the solution posted here you won't be able to run FreeRouting from within KiCAD, but you can run it separately in the NetBeans java development environment and then importing back the results of the routing to KiCAD. It will involve quite a few steps, but hey, you'll get autorouting at the end for free.
1. To get started download and install NetBeans from the official web site.
2. Install git, if you haven't done it so already. Here's how.
3. Open a terminal and navigate into a folder you're going to clone this repo to. Issue the following command:
git clone https://github.com/nikropht/FreeRouting.git
4. Follow the steps 2 to 5 described on this site at the bottom: https://github.com/nikropht/FreeRouting.git
5. Obtain the missing jh.jar file. I used one from git from this project. This one works:
https://github.com/kellertuer/Gravel/blob/master/javahelp/jh2.0/javahelp/lib/jh.jar
If you can't be bothered you can clone the whole project to get that single file by saying:
git clone https://github.com/kellertuer/Gravel.git
to your computer.
6. Then follow steps 6 to 10 from here https://github.com/nikropht/FreeRouting.git
7. Click the little play button for run in NetBeans, and Freerouting will fire up.
8. Load and arrange your design in Pcbnew and click Tools > FreeRoute
9. Choose export data to .dsn
10. Then launch Freerouting from within NetBeans and load the file you saved using the open your own design facility. It should look similar to this:
12. Click File > Export Specctra session file.
13. Go back to Pcbnew and click Back import the Specctra Session file. And click yes to rebuild the connectivity data.