Using say raspberry pi connect via Bluetooth/USB to gotenna and raspberry acts as server etc. Can then connect pi to larger Lan WiFi to serve others who do not have app. WiFi could act as distribution server for files to install (android only)
Piratebox Android raspberry was created Long before gotenna to allow for anonymous connections via WiFi and allows for anonymous chat. Message board and file savings.
I use similar system in mountainous terrain for events to share info. Screens and data via ubiquiti equipment with 10plus km links.
Using a web based WiFi system anyone can connect without apps. It’s amazing when people ask if WiFi is up in the middle of a forest to me. Others look confused.
WiFi hubs need to be implemented and maybe gotenna Mesh server should be created. To bridge networks and users phones.