Let's imagine User A. I want to build an application that detects all users of my app who are currently close to user A (in terms of real-life proximity). They should be able to send out ID's to each other to identify which users are currently around them. This should work cross-platform, so Android devices should be able to see iOS devices and so on. I'm using Flutter and have done some research but none of the example apps worked cross platform. So far I tried flutter_blue, beacon_broadcast and flutter_reactive_ble.
If someone has experience in this field, I would be incredibly thankful for some advice on how to approach this.
Thank you so much in advance!