Hi, the project sounds interesting.
I can make a little CRM to feed the JSON data.
I think I will be using Angular 7 for the CRM frontend and it will communicate with firebase to save the data.
For the android apk, I usually make my own REST API to communicate,
but for this case, maybe we can try to communicate to firebase directly?
since the CRM is feeding data to the firebase directly also.
Maybe we can talk about the detail more