If you use a bluetooth remote with your iOS device to trigger the camera shutter, change volume, etc, you should be interested in this:
https://www.kickstarter.com/projects/satechi/goremote-bluetooth-40-le-waterproof-remote-control
Waterproof, rugged, and Bluetooth 4 LE (They claim the battery can last 2 years).
https://www.kickstarter.com/projects/satechi/goremote-bluetooth-40-le-waterproof-remote-control
Waterproof, rugged, and Bluetooth 4 LE (They claim the battery can last 2 years).