Handles the specific weirdness of mobile web: the 100vh viewport bug that cuts off content behind browser chrome (use 100dvh instead), iPhone notches and safe areas, 44px minimum touch targets, and bottom navigation that doesn't break thumbs. Gives you working patterns for slide-out drawers, swipe gestures, and pull-to-refresh with proper touch event handling. The mobile-first CSS examples are solid, building up from mobile rather than media-querying down from desktop. Pairs well with PWA work since installable apps need this stuff dialed in. Not for native iOS or Android development, just progressive web apps and responsive sites where touch and small screens matter.
npx skills add https://github.com/erichowens/some_claude_skills --skill mobile-ux-optimizer