A Bitty Software application - http://www.bittysoftware.com
bitty controller lets you remote control BBC micro:bit connected devices like robots, cars or lights. It provides a choice of user interfaces including a series of on/off switches, a classic dual d-pad controller and an analog touchpad for fine control. Variants of the touchpad UI allow sensor data to be displayed and ancillary features like LEDs and servos to be controlled. It's basically awesome!
Note that Bitty Controller is also available as a web application for use from laptops, Chromebooks, PCs etc in BittyWeb at https://bittyweb.bittysoftware.com
The Bitty Software web site contains code examples and further information.
And if you're feeling adventurous, be aware that bitty controller can be used with any microcontroller which implements the BBC micro:bit's Bluetooth Event Service. More information can be found at http://www.bittysoftware.com.
New UI which provides a touchpad for analog control, ideal for driving vehicles and up to 12 buttons which send Bluetooth events to your micro:bit. Perfect for controlling ancillary features like servos and LEDs.
Up to six family members will be able to use this app with Family Sharing enabled.