The pitch is simple enough to be suspicious of: duplicate an artboard, move things, and the tool works out the transition. For a large class of interface motion, that turns out to be exactly true.

Where it holds and where it breaks

Position, scale, rotation and opacity interpolate cleanly as long as layer names match across boards. Rename a group and the element pops instead of moving, which is the single most common cause of a prototype that looks broken for no visible reason.

It struggles with anything that needs staggering. A list of twelve rows arriving in sequence wants twelve delays, and the tool gives you one easing curve for the whole board.

For handoff conversations it is more than enough. For production-accurate motion specs, you will still be writing numbers down somewhere.