Dolibarr is a good ERP/CRM app more information on this link would be good to have it as a snap.
Bellow is a quoted text from their page
Dolibarr ERP & CRM is a modern software package to manage your organization’s activity (contacts, suppliers, invoices, orders, stocks, agenda…).
It’s an Open Source Software (written in PHP language) designed for small, medium or large companies, foundations and freelancers.
You can freely use, study, modify or distribute it according to its Free Software license.
You can use it as a standalone application or as a web application to be able to access it from the Internet or a LAN.