ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.

Growhold - Growhold is a reputable customer data platform that advantages you with the data without the risk of losing user data privacy.

fusebill - Fusebill is the leading recurring billing and subscription management software for businesses. Try Fusebill for subscription billing made easy!

Upodi - Unified Commerce Platform.

MinuteDock - Web-based time tracking software designed to integrate with the Xero accounting package.

JustOn - JustOn offers electronic billing and invoicing solutions.