Blue Pie Apps use bluetooth to communicate with Raspberry Pi or linux-based devices.
                Use a phone or tablet to control a Raspberry Pi, or set parameters on the Raspberry pi, 
                only using using bluetooth (no wifi needed, no usb cable needed).
            
BTBerryWifi : Set the wifi network on your (headless) Raspberry Pi, using only Bluetooth. (see details)
                See it in the store:
                iOS, 
                Android,
                
                or search for: BTBerryWifi , on your app store.
 
            
                
                It is necessary to first install the bluetooth python code 
                on your Raspberry Pi (or compatible linux device).  
                It is Free (as in beer). And open-source.
            
                Instructions (ReadMe) and an automated install script can be found on GitHub:  
                RPi-SetWifi-viaBluetooth.
                Or see Installation requirements on the Raspberry Pi".