The apply with linkedin button allows you to apply for jobs on LinkedIn.
http://developer.linkedin.com/plugins/apply
Widgets
Get access to data on 1,353 websites that are Linkedin Apply Button Customers. We know of 191 live websites using Linkedin Apply Button and an additional 1,162 sites that used Linkedin Apply Button historically and 55 websites in the United States.
Get a list of 1,353 websites using Linkedin Apply Button which includes location information, hosting data, contact details, 191 currently live websites and an additional 41 domains that redirect to sites in this list. 1,162 sites that used this technology previously and 55 websites in the United States currently using Linkedin Apply Button.