A bunch of new apps are using Touch ID for privacy and protection, so why doesn't Apple implement touch ID for native apps? For example, it would be cool if I could enable Touch ID protection for my photos and other apps with sensitive information. Not even native apps, it could just be any of them. Can't count the number of times I've let a friend borrow my phone to watch a video or make a call, but get a little unnerved that they'll wander into an app they shouldn't be in. Just seems like it would be really easy to implement, yet it hasn't been done.