ShortStack - Shortstack is a website that allows you to create viral online events for your social media followers or other online audience.
Heyo - Use Heyo to easily create Sweepstakes, Contests, and Campaign apps that publish to Mobile, Facebook, and anywhere on the web.
HubSpot Marketing Hub - HubSpot is a cloud-based inbound marketing software that allows businesses to transform the way that they market online.
Contest Domination - Contest Domination is a contest software that allows companies to create online contests that spread virally and gather qualified leads.
Woobox - Woobox helps you easily create powerful contests, sweepstakes, coupons, and more to grow your fans...
ContestCore - See posts, photos and more on Facebook.