JRENG!

Brendon is a Render Region add-on for Blender that lets you set pixel-accurate regions in Camera view, save them to a list, and recall each with a single click from the panel.

Loki is a location keeper add-on for Blender by JRENG! that saves and recalls the X, Y, Z location of any object into a list, letting you store and restore positions at any time.