That being said, none of these 'freemium' features hindered the overall gameplay - in most cases, it was a lot of fun earning upgrades through play rather than paying for them. While all the games in this list are free to download, they also include in-app purchases that help make the game easier. And with so many games available in this genre, we wanted to show off ten of our absolute favorites. Whether it's terrorism or brain-hungry zombies you're neutralizing, first-person shooters are an awesome way to immerse yourself within a new world and kill some time with your iPad or iPhone.
