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

CalendarBudget - The easiest way to track and forecast your wealth - using a calendar.

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

Square Invoices - Square Invoices is a software that offers sellers an easy and affordable way to get paid faster, send invoices from mobile device or computer.

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.

Working Papers - Working Papers is flexible project management software solution.