Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.
Flowkey - The easiest way to learn piano with your iPhone or iPad
Recurly - Subscription billing and recurring billing management. Recurly offers enterprise-class subscription billing for thousands of companies worldwide.
Yousician - Learn to play music at home, at your own pace
Zuora - Zuora creates cloud-based software on a subscription basis that enables any company in any industry to successfully launch, manage, and transform into a subscription business.
Melodics - Melodics is a desktop app that teaches you to play MIDI keyboards, pad controllers, and drums.