As of my last update in September 2021, there are numerous online services and platforms available for web app development. These services can help you build, host, and manage web applications without the need for extensive programming knowledge. Here are some popular options: 1. **Wix**: Wix is a user-friendly website builder that also offers tools for web app development. It provides a drag-and-drop interface, templates, and a range of features to create web apps quickly. 2. **Webflow**: Webflow is a design tool that allows you to visually build web apps using a no-code or low-code approach. It's suitable for creating responsive and interactive applications. 3. **Bubble**: Bubble is a no-code platform specifically designed for building web applications. It enables you to create complex apps without writing any code. 4. **OutSystems**: OutSystems is a low-code platform that combines visual development with traditional coding to build web and mobile applications rapidly. 5. **Appg...