Show HN: Capsule – Single-file web apps that save their data into SQLite

Capsule is a novel web app platform that allows users to create, share, and run single-file applications, eliminating the need for cloud accounts, servers, or subscriptions. The entire app - including the user interface, media assets, and local database - is packed into a compact .capsule file, making it easy to share via familiar messaging apps like WhatsApp, AirDrop, or email.

When the recipient receives the .capsule file, they can tap it to launch the app instantly, with all data preloaded and ready to use. This seamless experience works on any device, including macOS, Windows, Linux, iOS, and Android, without requiring any setup or configuration. Capsule files are completely cross-platform, ensuring the same performance across devices.

Developers can write standard HTML and CSS code, and Capsule keeps all personal data securely stored on the user's device, free from cloud silos. This approach ensures complete ownership of the app and its data, providing a high level of privacy and security. Users can create and save various types of content, such as task lists, recipe notes, or project logs, all within the capsule file.