Cost / License
- Free
- Open Source (GPL-3.0)
Platforms
- Android
- Android Tablet
- F-Droid




OggSync is described as '’s mission is to keep mobile users in sync with the scheduling demands of a busy lifestyle, keeping all calendars in one manageable view! Whether it is a users’ Google or Outlook calendar, OggSync syncs to a users mobile phone quickly and automatically, allowing users see' and is an app in the backup & sync category. There are more than 10 alternatives to OggSync for a variety of platforms, including Windows, Android, Web-based, Android Tablet and iPhone apps. The best OggSync alternative is DAVx5, which is both free and Open Source. Other great apps like OggSync are EteSync, ICSx5, Outlook Google Calendar Sync and AkrutoSync.




Secure, end-to-end encrypted, and privacy respecting sync for your contacts, calendars and tasks. Everything is encrypted on the client-side and all the code (client and server) is open source.




ICSx5 is an Android app to subscribe to remote or local iCalendar files (like time tables of your school/university or event files of your sports team).




Offers calendar synchronisation between Outlook and Google, including attendees and reminders. Completely free, no install necessary, works behind web proxies and actively developed.




AkrutoSync automatically and privately syncs Outlook PC contacts, calendar, tasks and notes direct with any Android, Windows phone, iPhone or iPad. Keeps information out of cloud.




SyncThemCalendars allows you to block time in one calendar based on events in another calendar.
GO Contact Sync Mod is an open source tool to synchronize your Microsoft Outlook contacts with Google Mail. With this tool you do not need to enter your contact details more than once, always have the latest version everywhere: in Outlook and in Google.

gSyncit™ is a Microsoft Outlook add-in that allows for the synchronization of Outlook calendars, contacts, notes, and tasks with your Google account.




Free Outlook Plugin, which synchronizes events, tasks and contacts between Outlook and Google, SOGo, Horde or any other CalDAV or CardDAV server. Supported Outlook versions are 2016, 2013, 2010 and 2007.



One of the world's largest and most popular multiplatform services for backup/synchronization of contacts and photos from a mobile.




Funambol is the easiest way to keep your phone contacts and pictures in sync with your other mobile phones, tablets, and computers.




This utility synchronizes Outlook calendar and task list entries to a Google calendar, vice versa, and both ways. Create profiles to sync multiple calendars. Modify sync frequency, direction, and filters. Outlook 2007 to 2016 are supported.

