A few months ago, Satechi released a bluetooth camera remote trigger that can add additional features your DSLR camera may lack. Here's a fun video from the GearAddix team that shows a bit more about the Satechi Remote in use.
I originally thought this could render your phone useless while it's controlling the camera, but one thing noted in the video (above) is that the app can continue to control the camera even while texting, tweeting, reading emails, surfing the web, etc.
The Satechi Smart Trigger is a fully functional wireless timer remote designed to be controlled from your iPhone or iPad. Use the Smart Trigger app to control your DSLR camera with three unique shooting modes: REGULAR (basic wireless remote), MANUAL SHOT (long exposure), or TIMED SHOT
(techniques like time-lapses).
The Satechi Smart Trigger can be found via Amazon (Click Here)
Satechi Bluetooth Wireless Timer Remote For DSLR