Bolt.new

Bolt.new, from StackBlitz, prompts a full-stack app into an in-browser environment where you can edit, run, and deploy it. It is good for quickly turning an idea into a working front end plus backend without local tooling. The tradeoff is a token-consumption model where costs scale with project size, so a large or heavily-iterated app can chew through the monthly token allowance faster than you expect.