Taking underwater pictures with Lifeproof?

I have the Lifeproof Iphone case but it will not take pictures underwater. Is it because the water makes it harder to push the buttons? Am I supposed to be using a certain app?

Honestly, that is surprising. The case should allow you to take pictures underwater without any trouble. The water does not affect the buttons.
I would recommend to call Lifeproof, or wherever you bought your case for additional help.
Lifeproof's phone # is 1-888-533-0735 (toll free USA) otherwise, see this page: http://support.lifeproof.com/

I bought mine from these guys: http://www.quantum-wireless.com/manufacturers/lifeproof.html and the first case I bought got damaged during the shipping (no idea how that happened unless it was crushed by an elephant or so… ) but they were very helpful and exchanged it without any trouble. Maybe they can help you too.