Akaunting

The LibreServer system isn't primarily aimed at companies or institutions, but if you're a one person company or freelancer then having the ability to run your own accounting system and keep the data private and also backed up is useful. Akaunting provides a nice web based system for small business accounts, and is also quite usable within a mobile web browser.

Ports

Forward port 80 and 443 from your internet router

Installation

Accounts software can often be quite complex, and so you'll probably want to refer to the official documentation (https://akaunting.com/docs) for details.