I tried to download it but it demanded I add it to my homepage etc. Firfox blocked it and I thought that might be a good idea.
That’s very weird. I have never had to download anything. All I ever do is click on the “Cable” button and i runs its tests. I also use FireFox and have no issues. But I use “NoScript” Add-on for FireFox so maybe there is some embedded “download” adware script on the page I never see.
“NoScript” is highly recommended. It stops ALL pages from running java scripts. No more endlessly opening pop-ups or new windows.
You get a notification at the bottom of the page and you can then tell it OK to run content from specific places only and it will remember the next time you visit the page.