Bubble

Bubble is the undisputed king of the "no-code" movement for entrepreneurs and startups. While enterprise tools like OutSystems require professional developers, Bubble is designed specifically so a non-technical founder with a great idea can build a fully functional, complex web application (like a two-sided marketplace similar to Airbnb or an entire CRM system) without writing a single line of code. It provides a completely free-form, pixel-perfect visual designer. You drag a button onto the screen, and then use the "Workflow" tab to dictate exactly what that button does using plain English logic (e.g., "When Button 'Sign Up' is clicked -> Create a new User -> Send an email"). It natively includes its own hosted database, completely eliminating the need to understand SQL or server provisioning. Its massive API connector plugin allows it to talk to almost any other service on the internet. A founder can build an app that takes a payment via Stripe, sends a text message via Twilio, and updates a record in Airtable, entirely visually. While it has a steeper learning curve than a simple website builder like Wix, it provides infinitely more logical depth.