I’m working on a File Sharing application in Android. I came to see an app name InShare (Link: text), this application is very simple working and easy to use. The thing I don’t understand about this application is how does it works.
This application doesn’t create a hotspot and connect the second device to it and use socket to share files between them.
On the receiver side InShare will simply show a QR code to scan. It also shows the below details after the QR Code:
Hotspot: DIRECT-tl-88******
Password: RBS*****
The QR Code also contains the same details in it. But this is not a hotspot created on that device. When you scan the QR Code from the Sender device it will create a connection between these devices and share files between them. But the sender device is not connected to any Hotspot. This sharing will work even both devices are not connected to any kind of wifi.

Can someone explain to me the functionality of this application?

I have searched about the WiFi Direct and WiFi P2P connection but doesn’t find anything like creating a QR Code or providing credentials so the other device connect to it using the credentials.
What I do find is that Wifi Direct and Wifi P2P works like creating a peers discovery showing them in some kind of list and selecting the device from that list to connect to it.