Linux-Based Billing And Business Application Server For FREE use.
Bitcoin Alts portfolio tracker, email / text / alexa / telegram alerts
Small Business Appliance
Fullstack open source Invoicing application made with MongoDB
ALGO GST Billing Software
Rental Tracking and Accounting System
Invoice and office utilities program for customer managment
jBilling is a web-based enterprise billing system.
SplendidCRM is like SugarCRM but designed specifically for Windows