Send/receive/log BLE beacons in Android

Android devices can be used as BLE beacon receivers, loggers and transmitters with the nRF Connect app. For initial experiments, instead of buying BLE-specific beacon hardware, you can use old Android tablets and phones to setup a beacon network. You can also use laptops, Intel Edison, Beaglebone, and Raspberry Pi to transmit/receive BLE beacons. A typical application of such beacons is for indoor/outdoor position estimation and tracking. BLE beaconing adjustments include transmit beacon contents (de facto standard formats), BLE Advertisement period, and BLE Transmit power. BLE logging uses the nRF Logger app. to write to a log file beacon RSSI vs. time.