You can purchase the Supremery PS4 Smartphone Mount on Amazon for $19.95; http://amzn.to/1P4CtF6
This is the perfect solution I was looking for to connect my iPhone to my PS4 controller for easy access to the companion apps so many games come with nowadays. This is also handy if you want to stream videos while you game, maybe a baseball or basketball game while you play Witcher 3. If you buy this just be careful when removing it, the plastic that snaps together is really thin. I would recommend putting it on a second controller so you don't have to keep taking it on and off, unless you don't mind leaving it on your main controller. It doesn't get in the way either way, I just prefer a controller without the mount on it when I am not using the mount.