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

Froged - One click solution providing easy-to-use marketing, sales and support services to turn website visitors into happy customers.

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

Keep Your Friends Close - A free e-book about maximizing Customer Lifetime Value

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

ChatWoot - Open-source omnichannel customer engagement platform