There is a Samsung Android App on Google-Play called “micro:bit by Samsung Electronics UK” which allows you to connect your micro:bit to a Samsung phone using Bluetooth (I have successfully used a Samsung Galaxy S4, but it apparently also works with other phones and tablets that support BLE).
When running this App on your phone, you can (over Bluetooth) both:
(a) download Scripts onto the micro:bit, and
(b) use the micro:bit to control various functions of your phone (eg. take a selfie, or activate the phones vibrate function etc).
Step 1: The Initial PARING of Your Micro:bit With Your Phone or Tablet (over Bluetooth)
In order to “PAIR”, there are 3 pre-requisites:
(1) Your micro:bit MUST have a blank script loaded on it (over the micro-USB-port), otherwise you will not be able to get it into pairing-mode. (NB. A blank MicroPython script does NOT seem to work for this, so instead use a blank Block-Editor script [ from www.microbit.co.uk/create-code ] - this works fine for me.)
(PS.) For normal micro:bits, you can power the micro:bit from either the micro-USB-port, or from the white-JST-battery-connector.
Update: [Note that I did have a micro:bit which although it appeared to mostly work ok, had an issue of getting much too hot when powered from the micro-usb. However, this "hot" micro:bit had the fault that the back “Button-R” would only work when powered from the micro-usb port. This meant that for this micro:bit, you could only get into the "Bluetooth-PAIR" mode if it was powered from the micro-usb-port; (ie. it wouldn't go into "PAIR-Mode" [to connect to a new phone] if powered from the white-JST-battery-connector). BUT for micro:bits which are working properly, you can "PAIR" using either micro-USB-power or the white-JST-battery-power.]
(2) Your Phone or Tablet MUST be able to support BLE (Bluetooth-Low-Energy)
(3) Your Phone or Tablet should have the “Samsung-Electronics-micro:bit” application loaded
Also note that because the micro:bit uses BLE (the Low-Energy version of Bluetooth), it seems that you have to use the “Samsung-Electronics-micro:bit” application both to do the initial Bluetooth-PAIRING, and to do the subsequent Bluetooth-CONNECTION (and re-Connections). (IE. The phone’s normal default Bluetooth menus won’t connect to a BLE device.)
So, to do the initial Bluetooth-Paring, open the “Samsung-Electronics-micro:bit” application, click on “Connections”, and then click on “Pair a new micro:bit” and follow the instructions.
Step 2: The Subsequent CONNECTING (& Re-Connecting) of Your Micro:bit With Your Phone/Tablet
Once you have Paired, to CONNECT (and for all subsequent re-Connections as well), open the “Samsung-Electronics-micro:bit” application, and click on the top (previously paired) “VAPIT” button. Make a note of the small connector-symbol on the right of the “VAPIT” button:
* when the micro:bit is NOT connected, this symbol shows a WHITE DISCONNECTED plug & socket (see previous photo);
* when the micro:bit is successfully connected, this symbol shows GREEN CONNECTED plug & socket (see photo).
Note that you can CONNECT (or re-Connect”) the micro:bit to your phone when the micro:bit is powered EITHER from the JST-Battery-Connector-Power OR from micro-USB-Connector-Power: It is only the initial “PAIRING” which requires micro-USB-Connector-Power, all subsequent “CONNECT” or “RE-CONNECT” (and any other Bluetooth-Use) will work fine with your micro:bit powered from the JST-Battery OR from the Micro-USB-Power.
Step 3: Downloading Samsung Example Sketches Using Bluetooth
The “Samsung-Electronics-micro:bit” application has 4 example sketches, which you can Flash onto your micro:bit over Bluetooth as follows:
(1) Open the “Samsung-Electronics-micro:bit” application, click on the “Connections” button, and then , and click on the top (previously paired) “VAPIT” button (ie. so you connect to your micro:bit over Bluetooth)
(2) Once connected, go back one-screen, and now click on the “Flash” button.
(3) Next click on the example-sketch you want to try (eg. the “find my phone sample”), and wait until this example sketch is downloaded to your micro:bit (over the Bluetooth connection)
Once the sketch has downloaded, it will automatically start running. The above “find my phone sample” sketch shows a big red arrow pointing to the “Button A” (see photo at top of this post). If you press “Button A”, your phone will Vibrate and Shout something at you.
Finally, note that if turn-off your phone’s Bluetooth, or if you stop the “Samsung-Electronics-micro:bit” application, this will disconnect the BLE (Bluetooth Low Energy) connection, and pressing “Button A” will NOT cause your phone to Vibrate. To re-connect, just start the “Samsung-Electronics-micro:bit” application again, click on “Connections”, and click on “VAPIT” again. The “Button A” will now cause your phone to Vibrate again.
Step 4: Resetting the Bluetooth PAIRING
To reset (remove) the Bluetooth Pairing on the micro:bit, you have to use the micro-USB-port to upload a new sketch (eg. a blank or any other sketch), which apparently over-writes whatever Bluetooth pairing info the micro:bit currently has. If you used a blank sketch, this therefore allows you to re-start Pairing, and connect to another phone or tablet.