We needed a standalone invoicing application so looked around and ended up taking the PHP code from a PHP invoicing application and enhancing it (it was not production ready) and also changing it to meet the New Zealand IRD Invoicing Statement Requirements. It is now available for free, as it is an Open Source application. It runs as a web application, so requires a web server to run. You can setup the webserver on your workstation or have a separate database/web server. Of course, if you only have one workstation, then the database/web server will need to run locally.
You have 2 choices, you can run it using a Linux webserver or a Windows webserver. It is recommended that you use a Windows webserver if you are not technically inclined as there are some software packages available to setup the environment to allow it to run. With Linux you tend to be on your own but I can setup a new installation of this program in 10 minutes.
You can use a software environment called WampServer which installs the necessary software to make your pc a webserver which will then run the PHP invoicing software. This WAMP software is available here.
If you go down to the both of the following page, it tells you how the get the appropriate environment with the the C libabries. https://wampserver.aviatechno.net/?lang=en&prerequis=afficher
You can get a utility which will load all the required VC++ libraries here (makes life alot easier) https://github.com/abbodi1406/vcredist