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

Sensor Tower - Sensor Tower is a platform for app store optimization and app industry intelligence.

Pabbly Subscriptions - Pabbly Subscription is a recurring billing & subscription management software.

App Annie - App Annie is a marketing analytics tool available for apps of all kinds. With App Annie, you can track sales, traffic, and a variety of other factors pertinent to monitoring an app's trajectory.

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

appfigures - Cross-platform app store analytics for all of your mobile apps.