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 1,346 websites that are Linkedin Apply Button Customers. We know of 69 live websites using Linkedin Apply Button and an additional 1,277 sites that used Linkedin Apply Button historically and 32 websites in the United States.
Get a list of 1,346 websites using Linkedin Apply Button which includes location information, hosting data, contact details, 113 currently live websites which includes 44 domains that redirect to sites in the list. 1,277 sites that used this technology previously and 32 websites in the United States currently using Linkedin Apply Button.