Heh.
Considering the bending issue, not sure you want to put it on an arm strap, if your upper arm is long enough to accommodate it.
I've started using SPI belts (actually a knockoff that is suppose to be water/sweat resistant).
May also try something like this:
http://www.amazon.com/dp/B00ATIE5ZE/...=IF64H3K0NH65R
That pouch is 6 x 4 inches, which may be too big to have on your waist if you're doing some exercises which require bending your torso. That isn't big enough for the 6 Plus, supposedly they're going to come out with something slightly bigger.
I can get $310 gift card for my 5s but now I'm wondering if it wouldn't make more sense to keep it as a backup and for using at the gym, even if I do get a 6 Plus.