Bike Forums - Smart Phone mount

I'm looking for the most secure handlebar mount for my Galaxy s5 in a Lifeproof case. When my provider sold me the Lifeproof case I was told that Lifeproof made bike mounts for their cases and I could order them off their website. Well, I went to the Verizon website and there is only one Lifeproof bike mount I could find and it is for the iPhone 5. Then I tried the Lifeproof site and they only list mounts for the iPhone 4 and 5.

I do a fair amount of gravel grinding and singletrack, so I want something that will hold my phone securely even on washboard roads or through ruts and bumps. Any suggestions?