What is horizon achievement unlocker and what games work with it?

I am looking for an understanding about Horizon achievement unlocker. My son is an adult with autism and he plays games on xbox 360 and xbox one. They are mostly Lego Batman, Lego Star Wars, Lego Indiana Jones, Lego Hobbit, Lego Lord of the Rings, Lego Marvel Superheros, Lego Jurassic World, Lego Ninjago, Lego Incredibles, Lego Worlds, Lego Avengers, and Lego Dimensions. He also plays Epic Mickey 2, Angry Birds Star Wars, Tron Evolution, Sonic the Hedgehog, Sonic Generations, Start Trek, Star Wars Battlefront. He also plays Dead Island. That’s probably the only “intense” game he plays.

Anyway, he wants me to pay for diamond achievement unlocker. When I look online, I don’t see his games listed. Can someone please tell me how this works. I need to know specifics before I pay for it. I appreciate any help I can get about this.

The achievement unlocker allows you to unlock gamerscore achievements and will work for any Xbox 360 game he has played. It will not work with Xbox One games as they are not handled the same way.

OK, so I would have to sign up for monthly or annual Diamond for him to do the achievement unlocker for his 360 games?

The achievement unlocker is available in both membership durations.

One more question…he wants to get “DLC levels of achievement”. What is this and can he do it if I pay for the Diamond membership?

Thanks so much for your previous answers!

I have no idea what DLC levels of achievements are unless he is wanting to get achievements for game DLCs. If that is the case then there should be no issues doing so with the achievement unlocker.