Add ITFlow to Ticketing (#3408)

README.md

@@ -1970,6 +1970,7 @@ _Related: [Task Management & To-do Lists](#task-management--to-do-lists), [Softw
 - [GlitchTip](https://glitchtip.com) - Open source error-tracking app. GlitchTip collects errors reported by your app. ([Source Code](https://gitlab.com/glitchtip/glitchtip)) `MIT` `Python`
 - [Helpy](https://helpy.io) - Helpy is a modern, open source helpdesk customer support application. Features include knowledgebase, community discussions and support tickets integrated with email. ([Demo](https://demo.helpy.io), [Source Code](https://github.com/helpyio/helpy)) `MIT` `Ruby`
 - [Iguana](https://github.com/iguana-project/iguana) - Iguana is an open source issue management system with a kanban board. `CC-BY-SA-4.0` `Python/Docker`
+- [ITFlow](https://itflow.org) - Client IT Documentation, Ticketing, Invoicing and Accounting Web Application for MSPs (Managed Service Providers). ([Demo](https://demo.itflow.org), [Source Code](https://github.com/itflow-org/itflow)) `GPL-3.0` `PHP`
 - [MantisBT](https://www.mantisbt.org/) - Self hosted bug tracker, fits best for software development. ([Demo](https://www.mantisbt.org/bugs/my_view_page.php), [Source Code](https://github.com/mantisbt/mantisbt)) `GPL-2.0` `PHP`
 - [OpenSupports](https://www.opensupports.com/) - Multi language ticket system with FAQ, role management, metrics and canned response features. ([Demo](https://www.opensupports.com/demo/), [Source Code](https://github.com/opensupports/opensupports)) `GPL-3.0` `PHP`
 - [osTicket](https://osticket.com/) - Manage, organize and archive all your support requests and responses in one place. ([Source Code](https://github.com/osTicket/osTicket)) `GPL-2.0` `PHP`