Hello!
I have a special use case with the legacy app:
I run a local server on my motorhome, without internet connection. It is used to monitor various things like water level, door locks, solar charger, temperature, lights, etc. The system is working perfectly because the legacy app, server and lib is rock solid 
However, the only thing I really miss, is the notification functionality, which afaik, uses a google service, so it needs internet to work.
Does anybody know any workaround for this? @ScottB , @BlynkAndroidDev?
Thanks!