I have an Android phone with an OTG cable and SDR Touch and ADSB# - that lets me "see" any plane transmitting ADSB signals around me without any need for a network connection.
(I use that as part of my safety setup when flying drones. If I'm out of cellular connection or my iPad running FlightRadar24 fails, I have a backup self contained plane detection system.)
(I use that as part of my safety setup when flying drones. If I'm out of cellular connection or my iPad running FlightRadar24 fails, I have a backup self contained plane detection system.)