DAVdroid

Description

DAVdroid is the only all-in-one synchronization solution for both contacts and calendars based on WebDAV (CardDAV and CalDAV). The app is easy to set up and integrates perfectly with your favorite calendar/contacts app (including default apps). It can also be used seperately, if you either have CalDAV or CardDAV.
After installing the app, there will be a new account type “DAVdroid”. Add a DAVdroid account using Settings/ Accounts/ Add account to enter your server. See http://davdroid.bitfire.at/configuration for help.
Important note for all Android 4.1 and all Samsung users: There’s a bug that causes accounts to be lost after a device reboot. Please see https://play.google.com/store/apps/details?id=at.bitfire.davdroid.jbworkaround. For *Samsung users*: You can download DAVdroid in Samsung Store to avoid this bug.
Key features:
⊛ Use DAV calendars (CalDAV) and address-books (CardDAV) in a single app
⊛ Two-way synchronization (server ↔ client)
⊛ Native Android 4+ implementation
⊛ Flawless integration with your device and favorite apps
⊛ Easy setup (resource auto-detection)
⊛ Fast algorithms for high performance (CTag/ETag support)
⊛ Optimized for phones and tablets
⊛ Out-of-the-box support for Android 4.3
⊛ … and finally – it’s open source!
Get the best out of this app …
⊛ … when using with your own DAV server (Radicale, DAViCal, SabreDAV, Baikal, …) and HTTPS – so you own and control all your data while having the comfort of synchronization between various devices. Or use a hosted DAV service you trust or the one of your company.
⊛ … and combine it with Evolution / Lightning / etc. on your laptop / PC
Why is it secure?
⊛ Source code is available (see homepage)
⊛ No need for giving your contacts/calendars to Facebook, Google, etc. Use your own server (or a trusted one)!
⊛ SSL is recommended to protected your communication so synchronization is secure even when using open Wi-Fi networks.
Tested with:
⊛ Radicale
⊛ fruux.com
⊛ OwnCloud
⊛ Baïkal
⊛ eGroupware
⊛ posteo.de
⊛ MyKolab