DAVx⁵

★★★★★

Works great. You only have to set it up once (unless you’re adding or removing new lists/calendars), and then it seamlessly syncs your address books, calendars and tasks between your CardDAV or CalDAV server and your Android device, and you can use them with any app on your phone that uses the system calendars and contacts.

I can use my Nextcloud contacts with K-9, GMail, the built-in Contacts app or Fossify Contacts, and even for phone calls. OpenTasks works great for my to-do list. And I can use my Nextcloud Calendars with anything from Simple Fossify Calendar up through the Google Calendar app, and it all syncs up and down.

Task support is limited to a few apps: Tasks.org, OpenTasks and jtx Board.

Note: With Nextcloud, syncing may be faster with an app-specific password.

Local changes are synced up to the server immediately, while changes on the server are pulled down on a schedule. Since 2026, you can add the DAV Push app to your Nextcloud server and it’ll sync changes instantly to your phone (using a UnifiedPush distributor like ntfy or through Google). Now it’s even more seamless than it was before!