Gleam - Marketing apps designed to help you grow your Business
NewsWhip - Chrome extension that checks how viral your content is
RafflePress - RafflePress is the best WordPress contest and giveaway plugin. Grow your email list, followers, and website traffic with viral giveaways in WordPress.
Promo Self Serve - Launch a promotion across the internet in 90 Seconds
Viral Loops - Viral Loops is a viral and referral marketing platform to launch ranking competitions, sweepstakes, pre-launch and referral programs.
SocialRank - Graph search for TWTR. Filter by interests, location, etc