Invoice Ninja is a free, open-source solution for invoicing & billing customers. With Invoice Ninja, users can easily create and send professional invoices from any internet-enabled device. Clients can print invoices or download them as pdf files as well as pay online from within the system.
NetSuite is an integrated cloud-based business software that provides all the core functions your business needs to run efficiently including business accounting, CRM, ecommerce and ERP.
PieSync is capable of syncing the Individual Customers out of Netsuite 2-way with marketing apps, or your smartphone's address list.