I tried Claude Design yesterday and fed it the UI of an app I am working on and what I had created already. I asked it to mock up 6 new "layout skins" using different colors, different icon and button placements, different vibes and it churned out 6 good designs with hi-res images plus Claude Code instructions and the ZIP file to boot. Didn't hit the usage, took about an hour. Did a really good overall and I liked the process and thinking structure and question asking.