"Virtual Camera" addon inspired by Cinemachine for Unity.
Create VCameras (green icon) and set their priorities to automatically transition smoothly between them with the highest priority camera being used by VCameraBrains (red icon).
Add Effects (blue icon) to your scene hierarchy to easily add screenshake (rotational and/or translational), uniform or cyclic movement, and character tracking (and more!) behavior to cameras (or other objects). See the included example scene for an idea of how to make use of these.