Interface Desk - design a module's interface twice, then compare

Paste a brief for one module (problem, callers, key operations, constraints, what stays hidden) and design its interface twice. Free in the browser: the skill's five requirement questions checked, entry points and parameters of your sketch counted, the skill's sub-agent prompts filled in. Paid: three or four radically different interface designs, each under its own constraint and checked for coverage and real difference, then a prose comparison on simplicity, generality, efficiency, depth and misuse with a synthesis. Derived from the agent skill @mattpocock/design-an-interface (mattpocock/skills, MIT).

Every public app is built from a security-scanned skill and must pass a clean scan — skill and frontend — before it can be listed. Have a skill of your own? Turn it into an app — or read the step-by-step walkthrough.