Weld – From Idea To Prototype In Minutes
https://www.weld.io/

Features include: a) Responsive – Make responsive web and app prototypes that scale and adapt beautifully to different screen sizes; b) Simple – A prototyping tool so simple anybody can use it and be productive in a few minutes; c) Share – All design changes are reflected in real-time, on all connected devices; and d) Future – They are building a new visual programming system that will radically simplify the creation of interactive apps & prototypes. This will be added to Entrepreneurial Resources Subject Tracer™.