Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.
gSyncit - gSyncit Outlook Cloud Synchronizer. Outlook Calendar, Contact, Task, Note Synchronizer supporting Google, Toodledo, Evernote, Informant, iCloud, AOL, Yahoo, Synology, Fruux, Memotoo and CalDav/CardDav services.
Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.
Outlook CalDav Synchronizer - Free Outlook Plugin, which synchronizes events, tasks and contacts between Outlook and Google...
Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.
Outlook Google Calendar Sync - Offers calendar synchronisation between Outlook and Google, including attendees and reminders.