AutoCam

Creates a camera and animates it automatically, based on the objects you have selected in the scene.
Example usage: Suppose you are working on animation of a character, who
is moving quite a distance in 3d space (maybe a long walk, run, etc).
If you play the animation in the perspective viewport, you need to constantly keep
panning and zooming the viewport to keep the character in frame. This
script provides a camera which auto-tracks the character (or selected
objects) in the viewport, keeping it center of viewport, maintaining
the same angle which exists when you click the "create autocam" button.
Works well for quick previews.

Earlier, I used to link a camera to the pelvis of the character to
track , but it used to be annoying because you completely lose the
up/down and rotation of the pelvis.