Protopie

ProtoPie is the go-to tool for high-fidelity interactive prototypes that go beyond what Figma can do — it handles conditional logic, variables, sensor inputs (gyroscope, touch, voice), and cross-device communication without any code. Used by Google, Meta, BMW, and Samsung for complex interaction design including automotive and IoT. It’s not a design tool, so you build visuals in Figma first and import; the steep learning curve and $79/month Pro price make it overkill for simple web prototypes.