There are more than enough multiplayer mode in the new Watch Dog 2 game but if you need another, the developer will be offering you one next week.
The new multiplayer mode will be a four player party mode where players can walk around the Watch Dog 2 world and complete side activities with three of your friends. There is no real objective so players are free to wander around and do what they like.
According to Kris Young, the developer. They introduce this mode so that their players can work together and not compete against each other all the time. He wants their players to enjoy the city with their friends.
The update will be free and it will come with the new patch that will also fix some of the bugs that the game had. The update will arrive on the 4th of July.