The addon was outdated, it is now at 1.1.4 (the latest available). It seems that support for ForumRunner has been abandoned by Internet Brands (yes the vile company that destroyed vBulletin and brought the silly lawsuit against XenForo Ltd).
By all accounts the app should work but unfortunately I have no means of testing now as I am on Android and will not buy the app out of principle. FH is verified and published in the public directory. I shall try and do some more digging.