FullContact is an address book management system that has been designed to let you focus on your relationships, not your contact management. Is is multi-platform, and is able to sync your contacts across your devices and platforms, not matter what they are; iOS, Mac, PC. All your accounts are covered too, be that Gmail, Exchange, Office365, or Twitter.
With FullContact you can consolidate your contacts from across the web. FullContact supports combining Google Contacts, Microsoft Exchange / Office 365 contacts, your phone's address book, and your social media profiles in order to gain a total view of your connections.
FullContact lets you sync, backup and merge all your contacts, and what's more they are stored in the cloud, for easy access from whatever device or platform you maybe connected from.
FullContact lets you use tags to sort your contacts that way that you want. It also has a couple of really neat features such as the ability to attach notes to your contacts to remember important details, and you can automatically add photos, social profiles, company info, and recent social media posts to your contacts, in order to give you a total overview of your all your contacts.