Various packages exists to simulate a quadrotor in gazebo. RotorS, PX4SITL, Hector, etc are some of the few.
We use our own simplified gazebo plugins/simulator (https://github.com/KumarRobotics/mrsl_quadrotor)
roslaunch mrsl_quadrotor_launch gazebo.launch world:=levine
roslaunch mrsl_quadrotor_launch spawn.launch mav_type:=pelican mav_name:=juliett
This spawns a quadrotor with plugins for odom and so3_cmd under juliett namespace. quadrotor_control plugins have to be launched under this namespace.
roslaunch mrsl_quadrotor_launch controller.launch odom_topic:=ground_truth/odom mav_type:=pelican mav_name:=juliett mass:=0.5
Launch the GUI to control the robot. Change robot name to juliett
rosrun rqt_mav_manager rqt_mav_manager