Question: I need a service that provides a visual UI builder and codeless frontend logic to simplify app development.

If you're looking for a service that offers a visual UI builder and codeless frontend logic, Backendless could be a great option. It provides a full low-code app builder with a visual UI builder for quick UI development and codeless logic for frontend development. The platform also offers responsive apps for web and mobile, a real-time database, and built-in tools for user management and data management. It has flexible deployment options and integrates with third-party services like FlutterFlow and Bubble.io, so it can meet different business needs.

Another top contender is Bubble, a no-code app builder that lets you design, build, test and deploy production apps without writing code. It's got a drag-and-drop editor, customizable templates and pages generated by AI. Bubble offers scalable and secure hosting, collaboration tools for real-time collaboration and several pricing plans. Its focus on scalability and security means it's well-suited for serious apps you want to build fast.

AppMaster is another flexible option that offers a no-code approach to building production-level web and native mobile apps. It uses AI-generated code and a drag-and-drop interface to create data models and business processes. AppMaster offers one-click publishing and integration with cloud platforms, making it a good choice for businesses that want to build internal tools and customer-facing solutions quickly.

Last, if you're interested in a web-based tool with a visual drag-and-drop interface, take a look at FlutterFlow. It's got a UI builder with Flutter widgets and pre-built components, real-time collaboration and the ability to publish to app stores and custom domains. FlutterFlow integrates with Firebase and offers a range of pricing plans, so it's good for everything from small projects to larger teams.