If you're willing to get an IOS phone or tablet then I would direct you back to the already mentioned Camranger.
I'm getting very fond of mine. I've been trying to get a decent twilight shot of about 60 or 70 hummingbirds that hit our feeders for a last call the lat few days. D800 on a tripod, Camranger providing a wifi link to my iPad or iPhone with me sitting comfortably at a table 30 feet away watching via live view. From the iPad I can change focus, ISO, aperture and shutter as the light changes. Very cool.
In other situations I could do all the above and HDR or focus stacking. The control of your D800 is so easy and remote. No longer do I need to find that button and wheel combination to change mode or function ... It's there on my touch phone or iPad. Like I said I'm getting very fond of this combo.