I never see an app released for FreeBSD. There are usually Deb and rpm files.
I suppose FreeBSD adapts and releases some them in their ports. But how is the coverage?
Another issue is the hardware support. Does it have drivers for things like recent WiFi chips?
Normally you don't release an app for BSD specifically unless you want to offer a port. In which case software is usually built and if you need containerization you can put it in a jail.
It seems you would do well to install a FreeBSD vm/usb and give it a run. Their documentation is pretty good and their forums are helpful.
If they support flatpaks, it might be good enough.
What’s not to like, I’m curious?
The storage is cheap these days, if you consider downloads are large. Core apps are robust.