Runs on micromatch, not normal match. Micromatch is the mobile edition, but shows up in the same highscore table. Get it by making your browser really small and reloading. The link should look like this
It queries the main page for that word group, then tries to use that data to match the words. Currently, its super inaccurate, but it gets sub 4 second times about 10% of the time, so you will just have to keep retrying.
UPDATE! Version 3.0 is now able to solve in 2 seconds, not as good and not as reliable either but earlier versions broke. Version 2.0 is now able to solve in 0.3 seconds. Thats pretty good if you ask me.