Great case, but for small phones
This case is ideal for phones that are about the size of an iPhone 4, and the iPhone 5 might be too long. If you have an otterbox on it, it probably won't fit (too thick).
It straps on to any standard backpack strap. Overall, this was a great purchase because it does exactly what I need it to do, which is stay high up on my backpack strap for easy access.