Pusher

Pusher is a hosted API to help you build awesome realtime web and mobile apps.

Pusher provides a simple set of APIs and libraries that allow you to build rich realtime features in hours rather than days. With powerful developer tools, and libraries in tons of languages, it's a breeze to get up and running!

As a .CO-er, you could get a 12 months free on their Bootstrap plan. This allows you up to a 200,000 messages per day, and up to 100 users connected at any time.

Just sign up on Pusher.com for your free API account! Then upgrade to the Bootstrap plan and apply the discount code provided! Need to upgrade to the next level plan? No problem the code will work for any tier but give you varying level of discounts depending on the tier of the plan.