Requires Android 6.0 Marshmallow or later.
The app must have the 'App permission' labelled Location enabled on Android as "Opera needs location access to scan devices".
Requires OS X Yosemite or later.
Some MacBooks may not work: Check "About this Mac" / "System Report" / "Bluetooth" and verify that Low Energy is supported.
Requires iOS 11.0 or later.