Odoo - An all-integrated business app suite to unleash your growth potential.
BillGrid.com - BillGrid is an easy to use online invoicing, billing and expense management system that will save you time with tracking clients projects, expenses, invoices and payments.
ERPNext - The ERP Software that helps you take full control of your business. ERPNext is both powerful and easy to use.
ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.
DataNote ERP - DataNote ERP is a complete ERP solution built for multiple industries such as construction, engineering, food and beverages, metal processing, and healthcare, among others.
Elorus - A super-easy online invoicing & time tracking software