Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.

YesGraph - Boost viral growth by recommending who users should invite

Chargify - Chargify is the best online billing software for all of your Recurring Billing needs. Learn more about simplifying your Subscription Billing today.

NewsWhip - Chrome extension that checks how viral your content is

Recurly - Subscription billing and recurring billing management. Recurly offers enterprise-class subscription billing for thousands of companies worldwide.

Promo Self Serve - Launch a promotion across the internet in 90 Seconds