yes the project is still actively maintained, however the definition of actively may vary from person to person.
My problem is that I have a lot of things to do with my studies and work and also want to have a little bit of free time. That’s why I coudn’t work on InvoicePlane for the past months. However, a new release with several bugfixes and smaller features will be released in the next days.
So in comparison to other projects that have several maintainers or make a living out of their projects like InvoiceNinja, I sadly lack the time needed to push the project forward and add more features.
Feature requests can be voted on in the #feature-requests category. Please search for a feature before adding a new one to prevent duplicates.
Hope this answers your questions.