The Daily team is launching a new series on building a custom daily fitness app using WebRTC APIs, with a focus on online fitness classes where one instructor leads multiple students. The team has created an open-source demo app that covers basic functionality but lacks specific details for unique features, and will be adding these features over the next few weeks through code samples and quick posts. To help developers get started, Daily is providing resources such as the existing tutorials on building custom apps in various front-end frameworks, including Next.js, React Native, SvelteKit, Electron, and Vue.js. The goal is to provide a comprehensive guide for building a large, multi-feature custom daily fitness app that covers key use cases and features.