Works like the reference rotation tool, but instead of picking a rotation axis, it uses the object’s local XYZ axes. The default rotation is around Z-axis, pressing Shift will rotate around local Y-axis, Control will rotate along X-axis.
Object replacer. Replaces picked nodes with instances or references of one source node. Can keep original transformation. Useful when you want to update already placed objects.
Multi purpose copy-paste tool. Replicates transformation, material, UVW modifiers or coordinates (in valid mesh objects), visual appearance, layer, general properties (i.e. you can copy the “radius” from a circle into a sphere or cilindre), modifiers (It cannot copy topology dependant modifications) and others, from a source object to a target object or to a group of targets.
Both tools are designed to work on the viewports with a fair grade of visual feedback.