Unreal Engine 4
The Reactive Camera Component can be inserted into any actor and allow for the camera to react according to just 2 inputs (forward & right), in a variety of ways.
Perfect for Isometric, Top-Down, Racing, 2D Side-Scrolling, Third-Person games. Get it up and working in under a minute! Can be easily fitted into most of Unreal Engine project templates in seconds!
Huge array of options (10+) to configure how you want your camera to behave according to input. Camera can zoom in/out, change FOV, tilt, pan. Everything happens automatically, in the way you want based on the input you provide.
All it requires is to have a camera system that consists of a camera component attached to a spring arm component (most of UE4 project templates have that setup already) and it will work right away!
You can enable/disable the component at runtime, plug-in player inputs to drive the reaction, plug-in Timelines or other graphs to drive the input. Can be used along all other already existing properties of the standard Camera Component.
Unreal Marketplace link: Reactive Camera