Key Selected Objects adds much-needed multiple-object keyframing options to Blender’s context-menu. If the target property is multi-dimensional (i.e. a property with X, Y, & Z values), you’ll get the options to create & delete keyframes on a single dimension for all selected objects. If it’s a single dimensional property (e.g. a Light Object’s “Power”), you’ll just see “Keyframe All Selected Objects” and “Delete Keyframes for All Selected Objects”.