My 5s doesnt work connected to the USB port, and have tried multiple known good cables. I think some models of iPhone will work and others will not.

I got this button a few weeks ago, used strong velco to attach it to the top of the left bar control - nice flat spot for it. Very difficult to use it with gloves on, and sometimes it takes several pushes of the button for it to work. This is after making sure it is paired, and works with each button press after startup.