QuickBooks Online - QuickBooks Online is a Cloud Accounting for small business that can be used on iPad, mobile phone or computer to do invoicing, billing, run reports, or even pay employees online.
plenigo - Modern publishers use plenigo to manage their subscription business for digital and print products. The software-as-a-service platform contains all the functions you need to successfully implement digital business models.
HarmonyPSA - HarmonyPSA - Professional Services Automation (PSA) for IT Businesses
Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.
Xero - Xero is online accounting for your small business.
billwerk - The All-in-One complete solution for subscription management and recurring billing.