Okay, in order to install this app, a security prompt came up warning me that allowing apps that are not from the market could be dangerous....yeah, yeah, I triggered it off momentarily to allow the installation of the nfl mobile app apk file and it installed successfully and works magnificently....good stuff for that.
HOWEVER....I want to go back and trigger that security back on. How do I go about doing this?
Edit: Okay, I found out how to reset the disabling of the security of apps. You go into settings on the home screen, go into apps settings and I believe it's the first option. check the box and you're good to go.