The sophisticated Watch Dogs script modification has been created by hacker JulioNIB and integrates the game mechanics from Watch Dogs into GTA V. He’s gone to such lengths as to create a custom animation for the Aiden Pearce, the lead character in Watch Dogs. Even the one-handed gun is held the same way.
In terms of game mechanics, you can accelerate cars into oblivion and completely screw with the traffic department’s standard red and green lights. Several objects strewn about the world can be turned into volatile bombs; at one point the player in the video above turns an NPCs phone into a combustible health hazard. Pedestrians that attempt to remedy the situation by calling the police lend themselves to easy exercises in damage control. And you can totally listen in on those conversations.
There’s even an added remote control hack to drive vehicles through your character’s phone, though this basically means switching perspective to the front panel. Should you act a little too wildly, the police can set out a search signal to locate you if you use your phone within a certain radius from their designated zone. There are even small details like cameras to hack, lights to turn off, and the white line matrix that connects all digital devices in Watch Dogs.
In terms of mods, this is very elaborate and seems well integrated with the overall mechanics of the original game. JulioNIB is a well known hacker who’s also responsible for having a frustrated, giant green superhero running through the streets as well as a custom jetpack. The mod can be found via the creator’s blog and is only available on PC.