While I disagree with their claim of being the “… first super-hydrophobic spray for iPhone” I think they are one of the first to make a kit that users can do at home. The Impervious Invisible Waterproofing Kit makes it pretty easy to waterproof/protect your smartphones exterior. If you want it to be truly waterproof (as in IPX-7) then you have some work ahead of you. While it isn’t impossible, it will take some steady hands and patience.
The full waterproof kits come with some tools for disassembling your smartphone so you can waterproof the guts of the phone. You can get the kit for about $35 here. Watch the video of this stuff in action after the break.