Can a prompt replace Thunkable?

Build a block-based visual programming editor for simple app logic, Thunkable's actual origin and differentiator, distinct from this catalogue's Adalo and FlutterFlow entries, which generate screens from a data schema rather than compiling visual logic blocks. Use a block-editor library like Blockly, Google's open-source visual programming toolkit, the same category of tool MIT App Inventor and Thunkable itself are built on, for the drag-and-drop block canvas. Implement a small, fixed set of blocks: event blocks (when button tapped, when screen opens), action blocks (navigate to screen, show message, set a variable), and condition blocks (if/then). Compile the assembled blocks into a small Expo (React Native) app's logic — each block maps to a corresponding React Native code snippet, generated and bundled into a real working app. Provide 2-3 pre-built screens, not a screen designer, so the focus stays on the block logic connecting them. Do not build a large block library, a component marketplace, or one-click store publishing — those are out of scope; this demonstrates the block-to-code compilation pattern with a deliberately small block set, not Thunkable's full library. Requires hosting only if you want to preview builds remotely; Expo Go lets you test locally without it.