In early 2018, Google has launched the Nearby Share feature that that allow inter-device data transmission between Andropid phones. Recently, it is stated that Google will be enhancing feature of the Nearby Share.
The Nearby Share works similarly with Apple’s AirDrop that allow wireless file transmission between public and contacts. After 5 minutes of public file transmission, this feature will be switched to transmission to people within contacts.
Google is also developing a new feature where it can share the feature to multiple people.
In short, the Google Nearby Share feature is supported on smartphone with Android 6.0 and above and works through Bluetooth Low Energy , P2P WiFi and WebRTC for wireless transmission.