Saving Sessions with the Facebook iOS SDK

Recently I added Facebook image sharing to Glory Math 1, and it was my first experience with the Facebook iOS SDK. I used the newer Sign Sign-On feature, which briefly takes the user to the Facebook app to ask them whether your app can access their Facebook profile. The docs are good, and the whole process was pretty straightforward, but one aspect of the authentication process really annoys me: Every time my app launches again, the user must go through the authentication process with Facebook. The first time the user authenticates, it'll ask for access, but every time after that, it just tells the user that they already approved the application for access, and they just have to tap "Okay". This process seems pointless to me. So, I tried to find a way around it.