The actual Final Theory isn't expounded on the site, IIRC, so here it is for those who would like a chuckle:
The simple and basic idea behind The Final Theory is that all matter is expanding at 4.9m/s^2, and therefore objects (close to Earth) appear to accelerate towards it at 9.8m/s. Great, huh?
Yes, that is the only case for which the hypothesis works for, and you can have fun thinking about the enormous number of properties of gravity for which it is obviously and completely wrong. There's a record of email correspondence between the author and someone with some critical thinking skills at homepage.mac.com/ruske/ruske/finaltheory.html (sorry for not making that a proper link, but I still need 4 more posts to level up and gain the "post link" feat lol)
He then somehow generalises this chronically flawed hypothesis to magnetism, although God only knows how.