Skyscanner - Skyscanner.com compares over 1000 airlines to find you the cheapest airfares, fast.

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

KAYAK - KAYAK is a travel search engine that searches hundreds of other travel sites at once. Our helpful tools & features find you the information you need to make the right decisions on flights, hotels, rental cars and vacation packages.

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

Momondo - Find cheap flights with Momondo.

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.