So I’m the primary maintainer of IN4 and 5.
IN4 is still working and can be installed manually. It was pulled from the catalogue and replaced with IN 5 (personally I wouldn’t have pulled it as it still works…). I’ll try to update the app when new versions of IN4 get published.
That said: IN5 is working now and ready for usage, with many thanks to @ericg for helping me with getting it to work. See the announcement here: Invoice Ninja 5 ready for usage
It may be rough around the edges but I’m hoping you users will file issues with things that don’t work so we can fix them.
Migrating data from IN4 to IN5 worked for me multiple times now, using the documentation from here: Free Source Available Invoicing, Expenses & Time-Tracking | Invoice Ninja
Important: There’s no upgrade-path from 4 to 5 (the developers of IN did this on purpose) so you have to install IN5 alongside IN4 and then migrate the data.
If there are any questions or problems, feel free to ping me here. 