Remember "room" when saving as app

[PatrickHonorez]

Since this is a PWA, it can be saved locally. However when doing that, the "room" (maybe I should call that otherwise?) is not saved, and therefore I have to pair the devices again.
I would have liked to have the full url saved (example: https://drop.lo/ROBERT
I was also wondering: if the internet access is dropped, will the file tansfer on the local wifi continue ?