Nymeria's browser extension enables you to find personal and professional email leads with the click of a button.
It has a nice add-on feature which brings up emails when browsing within LinkedIn. Very handy for recruiters!
The guys at SmartReach.io have created a pretty cool plugin for LinkedIn and Gmail. Find contact details while browsing LinkedIn, or directly within gmail as you are composing a new message.
We think the Gmail email finding feature is pretty cool, and definitely unique. If you use Gmail a lot, and outreach to many people on a case-by-case basis, we'd recommend it!