LinkedIn Sales Navigator for Gmail (formerly Rapportive) is a free Chrome Extension that shows an email recipient's LinkedIn details within the user's Gmail inbox, and allows users to jump to the contact's LinkedIn profile.
Rapportive was acquired by LinkedIn in 2012. In November 2017, LinkedIn released a new version of Rapportive called Sales Navigator Lite for Gmail, which makes some features of LinkedIn Sales Navigator accessible from within user's email inbox. A subscription to LinkedIn Sales Navigator
unlocks premium features in the Chrome extension for Gmail.