DAVdroid 是 Android 4+ 上的一个开源的 CalDAV/CardDAV 同步应用解决方案。
关键特性：
two-way-synchronization (server ↔ client, server always wins)
focused on simplicity, security and privacy
native Android 4+ implementation
lightweight application, not cluttered with “features”
flawless integration with device and address book/calendar apps
high-performance algorithms
seperately usable (either CalDAV or CardDAV)
free and open-source software (FOSS)
界面截图：
