SilentSuite offers end-to-end encrypted synchronization of calendars, tasks, and contacts across web, Android, Apple Calendar, Thunderbird, and self-hosted servers, ensuring all data is encrypted locally before syncing to the server. The service supports open standards like CalDAV and CardDAV, is open source, provides a hosted option with a clear pricing model or free self-hosting, and emphasizes privacy by design without data mining or vendor lock-in.
