Asos is (yet another) app locker for iOS 7/8. It is currently available on the BigBosss repo for $0.99.
Warning: this code is awful. Ridiculously, hilariously, ludicrously awful. I would not recommend it for any purposes other than laughing at me / learning how to do very specific things.
Don't try to use this code as a learning resource - I haven't read it in 4 months, but I can almost gaurantee it is obtuse and implemented weirdly.
I'm sorry :)
Open sourced on GPL v3.0. Basically, don't be a dick, and if you make something on this code or learn something significant from it, I'd love a shoutout :-)