info@bitfire.at
concerning apps: play@bitfire.at (PGP )
+43 664 5580493 (no app support; please send a short email/SMS before calling because we get many spam calls)
bitfire web engineering GmbHDAVx⁵ integrates CalDAV/CardDAV into Android! GPLv3, available in various stores.
More than 100,000 licenses sold. Winner of the Constantinus Award 2014 (category: open-source).