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.

Odoo - An all-integrated business app suite to unleash your growth potential.

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

Insightly - Insightly is the easy, powerful and affordable online Customer Relationship & Project Management Software used by over 400,000 small businesses world wide

Elorus - A super-easy online invoicing & time tracking software

ERPNext - The ERP Software that helps you take full control of your business. ERPNext is both powerful and easy to use.