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. **Appgyver**: Appgyver is a platform for building web and mobile applications with a visual development approach. It supports integration with various data sources and APIs.

6. **Microsoft Power Apps**: Power Apps is part of the Microsoft Power Platform, offering no-code and low-code tools for building custom apps that integrate with Microsoft 365 and other services.

7. **Google AppSheet**: AppSheet, acquired by Google, is a no-code platform for building apps that integrate with Google Workspace and other data sources.

8. **Zoho Creator**: Zoho Creator is a low-code platform from Zoho that allows you to create web applications and automate workflows with ease.

9. **Mendix**: Mendix is a low-code platform that enables developers of all skill levels to build web and mobile apps with pre-built components.

10. **WordPress**: While primarily known for blogging and website building, WordPress can also be used to create simple web applications using plugins and custom code.

Before choosing a specific online service, consider factors such as your project requirements, budget, scalability needs, and the level of technical control you desire. Each platform has its strengths and limitations, so it's essential to pick the one that best aligns with your development goals. Additionally, since the tech landscape is constantly evolving, there may be new platforms or changes to existing ones beyond my knowledge cutoff date. Always research the latest options and read user reviews to make an informed decision.

As of my last update in September 2021, there are numerous online services and platforms available for web app development. These platforms offer various tools and features to facilitate the creation and deployment of web applications without the need for extensive coding knowledge. Some popular web app development online services include:

1. **Appgyver**: A low-code platform that enables users to build web and mobile apps visually with drag-and-drop components and minimal coding.

2. **Bubble**: A visual web development platform that allows users to create web applications without writing code. It offers a range of customization options and integrations.

3. **OutSystems**: A low-code platform that supports the development of complex web applications. It provides various templates, modules, and drag-and-drop functionality.

4. **Webflow**: A visual web design and development platform that allows users to create responsive websites and web apps without writing code.

5. **Microsoft Power Apps**: A low-code platform that allows users to build custom web apps and connect them to various data sources.

6. **Zoho Creator**: A low-code platform that enables users to create web applications for various business needs without extensive coding.

7. **Mendix**: A low-code platform that supports web and mobile app development with a visual interface and integrations.

8. **Wix Code**: A platform that extends the capabilities of Wix's website builder by allowing users to create dynamic web applications.

9. **Google AppSheet**: A platform that lets users create web and mobile apps from spreadsheets and data sources without coding.

10. **Appian**: A low-code platform that offers rapid development and deployment of web and mobile apps.

Keep in mind that the online services and platforms landscape may have evolved since my last update. It's a good idea to explore and research the latest options to find the platform that best suits your specific needs and requirements. Additionally, always review the terms, pricing, and features of each platform before making a decision.

As of my last update in September 2021, there are numerous online services and platforms that cater to web app development. These services typically offer various tools, frameworks, and hosting options to simplify the process of building, deploying, and managing web applications. However, please keep in mind that the online landscape for web development services is constantly evolving, so there might be new platforms or changes to existing ones beyond my knowledge cutoff date.

Here are some popular online services for web app development that were well-known as of September 2021:

1. **AWS Amplify**: Amazon Web Services (AWS) Amplify is a full-stack development platform that provides a set of tools and services for building scalable and secure web and mobile applications.

2. **Microsoft Azure App Service**: Microsoft's Azure App Service allows you to build, host, and scale web applications easily using .NET, Java, Node.js, Python, or other popular frameworks.

3. **Heroku**: Heroku is a cloud platform that lets you deploy, manage, and scale applications effortlessly. It supports various programming languages and integrates well with popular web frameworks.

4. **Firebase**: Firebase, owned by Google, offers a suite of tools for developing web and mobile applications. It includes real-time databases, authentication, cloud functions, hosting, and more.

5. **Netlify**: Netlify is a popular hosting platform that simplifies web app deployment. It supports continuous deployment, serverless functions, and other modern web development features.

6. **Vercel**: Vercel is another hosting and deployment platform known for its ease of use and support for serverless functions. It is well-suited for Next.js and React-based applications.

7. **Glitch**: Glitch is an online code editor and hosting platform that allows you to quickly create web apps, remix existing projects, and collaborate with others in real-time.

8. **CodeSandbox**: CodeSandbox is an online IDE (Integrated Development Environment) that specializes in providing an easy way to build, test, and share web applications in the browser.

9. **CodePen**: CodePen is a social development environment for front-end web development, allowing you to build and showcase HTML, CSS, and JavaScript projects.

Before choosing any specific platform or service, it's essential to consider your project's requirements, scalability needs, budget, and the technologies you plan to use. Additionally, check for the latest updates and user reviews to ensure that the platform is still relevant and reliable.