Google Sync is a free Google service for syncing Mails, Contacts, etc across devices.

Zoho CRM is an online customer relationship management software for managing your sales, marketing & support in a single system.

gSyncit is an Outlook cloud synchronizer.

Microsoft SharePoint is a browser-based collaboration and document management platform.

Soocial provides a synchronization service that syncs contacts between the users' computers, phones and web apps.

AkrutoSync helps you automatically sync Outlook across all devices.