Contacts+, formerly Full Contact, is a contact management tool for professionals and teams which automatic syncs address book updates between cloud accounts—Google, iCloud, etc. [1] Their software transforms partial identities into complete profiles by pulling information from web, social, and more.
Their 🏷️#browser-extension provides enriched context about contacts, without leaving your inbox. Quickly update details, add tags, and make notes in the sidebar of your inbox. [2] Their APIs enable you to create a number of powerful flows with software like 📝MailChimp, 📝Zapier, etc.
I first discovered Full Contact when it was still in beta by the recommendation of 📝Brad Feld.