Google published a Gemini walkthrough on November 5 showing how a photograph of a hand-drawn sketch — an app mock-up, a habit tracker or a game board — can become a working web app. The flow is three steps: upload the photo, select the Canvas tool and ask Gemini 'Can you code this app?', then test the result in the preview window and refine it by chat.

Gemini reads the visual, writes the code, and can adjust colours, fonts or features in real time. For apps that need to remember data between sessions, Google's documentation says Gemini automatically provisions a Firestore database instance.

That convenience carries a privacy bound Google flags itself: Canvas apps are shared through public links, and anyone holding the link can view and edit the shared data. Google published no benchmarks for how faithfully the generated code reproduces a given sketch.