I once bought a set of headphones that came with an armband for my phone. I became a big fan of holding the phone up high on the arm. Soon after I tore it trying to fit credit card, building id card, car key, etc etc in there. the armband adjustment was just folding the material - pretty cheesey.
Then I bought a bigger phone and had to retire this thing. I went to carrying phone in my hand! Or using 'Ultra' style vest just to have my phone with me. Carrying it in my hand cost me $hundreds in cracked screens. You never think you're going to trip... until you do. :(
This new mofo from ArmPocket has it all. It's roomy, extra pocket inside for incidentals. There is a strap that keeps phone pressed against the inside of the clear plastic. Touchscreen work just fine. If you have Siri (or equivalent) you can execute quite a few commands by telling her what to do.
Easy to use adjustment strap. Extra Pocket. Velcro to hold extra headphone cable. Unzips/zips easily. Touchscreen work through plastic.
The bads: Still searching for a downside. Will take getting used to if you're new to an arm band, like you have to think through how to shed/add layers. My only issue, and this seems silly- the zipper tabs are metal and there's two of them. They *clink* together and I think there's something moving in the woods :). Maybe it's just that I need to relax a little.
If you have to carry a phone, use this product.