I just recently found out about Flock by Open Whisper Systems. Aaaaaaand then they decided to shut it down.

Flock has these features that I like:

  1. The company has a great reputation in the security/privacy field.
  2. Secure sync'ing of calendar and contacts.
  3. You can pay them for a service or roll your own server.

I didn't like that it required a server. I would have preferred an option for local-only to be in the mix.

Are there any competitors in this market? I didn't think there were when I stumbled across Flock, and was very excited to hear about it. I haven't used it yet though, since my intent was to stand up my own server and I never got around to that.

Are there any other secure calendar and/or contact managers for Android out there?

  • connectionsapp.us provides local-only private contact storage; I'm hoping they will add a synching service or synching options also (disclosure: I know and trust the company founder).
    – mlncn
    Commented Aug 13, 2015 at 9:36
  • Like DavDroid, fruux.com is also based on WebDav, but has the additional option to pay to host on their servers.
    – mlncn
    Commented Aug 13, 2015 at 10:02
  • That's not what the OP asks: No syncing, no calendar.
    – user416
    Commented Aug 13, 2015 at 10:06
  • I would consider that competition in the field. However, the URL no longer works :-/ Commented Jan 26, 2016 at 3:38

2 Answers 2


There is https://davdroid.bitfire.at/what-is-davdroid which is fully Free Software and available in the https://f-droid.org/ app repository and works with any Dav server, including OwnCloud.


I know this question is old, but I just came across it and thought I'd share. I think EteSync is exactly what you are looking for.

Your Data, Yours Only.

Secure, end-to-end encrypted and journaled personal information cloud synchronization for Android and the desktop. Currently supports contacts and calendars, with more on the way.

EteSync costs only $14 a year with no hidden fees. Sign up now for a two week free trial. No payment info required! Alternatively, you can run your own server for free.

it's recommended by privacytools.io

EDIT: I recommend this app because it's an open source project which does end to end encryption Calendar and contact sync for Android, just like flock used to do.

  • You are supposed to tell why. FWIW this could just be a spam message.
    – user416
    Commented Jul 13, 2017 at 12:35
  • Sorry about that
    – fbwnd
    Commented Jul 13, 2017 at 12:49
  • at the moment there is no iOS app for EteSync Want an iOS app? Show your interest here.
    – Sybil
    Commented Nov 7, 2018 at 12:43

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