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

Free-Invoice.co.za - Free Invoice Software | Free online tool that helps small businesses to generate free invoices and manage their contact list. It can be used as an alternative to expensive invoicing software and online invoicing applications

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

Invoice Template - Create beautiful looking invoices in seconds

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.

Bookipi Invoice App - A minimal, beautiful invoice app for freelancers