The point of this hack? Well, basically nothing. The in-game phone interface still appears, so if you though using this won't cover a portion of screen, then I must disappoint you; accessing the smartphone with the same input device that you use for the rest of the game is significantly faster than putting down the controller/letting go of the mouse, reaching for the phone and using it.
Functionality is a tad limited, as you can use the phone to scroll through the in-game menu, but the messages themselves don't appear on the phone, and when in camera mode, what appears on the in-game camera, doesn't do so on the phone. The reasons for this is obvious, as these involve data coming from the game that isn't present on the iPhone, which is only used as an input interface, and game data isn't stored on it.
All in all, this is a neat little feature, that Rockstar honestly should have made themselves. Considering the boatload of companion app GTA V has (like our own, check it out!), making an official smartphone interface app is an absolute no-brainer. The camera probably wouldn't have worked the same way even so due to the hardware limitations, but the messages and whatnot would surely function fully on an official release.
Would you guys use this app if it was ever publicly released?