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!
Find real emails for people at any company. Anymailfinder is a competitor to Hunter and has one key advantage, it only charges for server verified emails. Pattern matched emails are free. You can test it for free.
As any of our own users will know -we're big fans of live 1-on-1 support, and Anymail Finder are pretty good at it.