You can use Buffer to publish your JobBoard.io RSS feed to Facebook, Twitter, LinkedIn and Google+.
You can also use IFTTT to automatically publish your JobBoard.io RSS to Twitter or Facebook
You'll need to create an IFTTT account, then, when prompted, enter your RSS feed of jobs. You can access an RSS feed of your jobs in JobBoard.io under Job Settings -> Syndication.
These will be posted automatically.
Updated 4 months ago