It is possible to easily carry your smartphone while running. The smartphone stays at the right place while you are running with the help of the smartphone holder. The smartphone holder can be attached tight at the upper arm. The smartphone in the holder can be used because of the transparent window.
Nathan is using the anti-slip layer. Because of that layer the smartphone stays at the right place without putting it in a case. The hipster can also be used as a smartphone holder, every size of smartphone fits in it.