Turn off your smart device's Bluetooth. On both Android and iOS devices, Bluetooth settings are part of the Settings app in your list of apps.
Turn off your smart device. On both Android and iOS devices, holding down the power button along the top or side until the screen goes dark will power off the device.
Power your smart device back on. Again hold down the power button until the screen turns on.
Turn your smart device's Bluetooth back on in its Settings app.
Reconnect your smart device to your NODE in the Variable app you are trying to use.