One of the best cross-platform CMS options you can use with Flutter to build web, iOS, and Android apps is Strapi. Strapi is a headless CMS that allows you to create and manage content, which can then be consumed via APIs in your Flutter applications.

Key Features:

• Open Source: Strapi is open-source and customizable.
• Headless: It delivers content via RESTful or GraphQL APIs, making it suitable for any front-end framework, including Flutter.
• Extensible: Easily add plugins to extend its functionality.
• User-Friendly Admin Interface: A clean and intuitive admin panel for managing content.
• Self-Hosted: Complete control over your data and hosting environment.

How to Integrate with Flutter:

1. Set Up Strapi: Install Strapi on your server and configure your content types and APIs.
2. Consume APIs in Flutter: Use Flutter's HTTP package to fetch data from Strapi's API endpoints.
3. Build UI in Flutter: Design and build your app's UI to display the content fetched from Strapi.

Why Strapi?

• Flexibility: Easily adapt to various project requirements.
• Community and Support: Active community and plenty of resources.
• Performance: Efficient in handling high traffic.

Using Strapi with Flutter allows you to manage your content centrally while delivering a seamless experience across web, iOS, and Android platforms.

For building web apps and iOS/Android apps with Flutter, consider CrafterCMS or Strapi. ButterCMS is also highly rated for cross-platform development with Flutter. Each CMS platform offers different features, so explore them to see which best fits your needs.

Easiest Headless CMS Options for Flutter:

• ButterCMS: Known for its ease of use and developer-focused experience. Offers a component-based editing interface and pre-built Flutter libraries for a quick setup.
• Contentful: Provides a user-friendly interface and extensive documentation for beginners, with features like content previews and localization.
• Strapi: An open-source option offering customization control. It may have a steeper learning curve but provides flexibility for developers comfortable with Node.js.

Choosing the right CMS can enhance your cross-platform development with Flutter, ensuring a smooth and efficient workflow.