Now I may stand corrected in a few weeks to come but currently there are no websites that provide much information on the ability. Smogon say 50% increase (which is what they are currently using on Pokemon Showdown) to these moves however Smogon have got a lot of information wrong so far and failed to provide a source. If this was to be incorrect I think it would more likely be around the 20% increase mark similar to the ability Iron Fist and Tough Claws. Take your pick.
As for the moves affected by the ability, this will be the following: Crunch, Bite, Fire Fang, Poison Fang, Ice Fang and Thunder Fang, all of which are confirmed to be learnt (in some way or another) by Tyrantrum however again this information is from Smogon.
If I get any updates and specifics I will be sure to update the answer and bring conformation but at this point it is far to early to know.