Here's a few more 4Tronix micro:bit accessories for ya!
bit:zero
The bit:zero is different to other edge connectors - it's reversible, with two rows comprised of ground and 3v pins, to fit directly on a breadboard or jumper leads. Unsoldered headers offer flexibility to solder above or below, or just solder leads direct to the PCB.
power:bit
The power:bit is great for schools, providing an alternative to broken JST leads on standard battery cages, using the edge connector to provide power from 2 x AAA batteries (not included).
angle:bit
The angle:bit is a 90-degree adaptor keep micro:bit always facing the right direction for your projects. Convert from laying down to standing up and vice versa. This is great for robots like the bit:bot robot (not included but available separately), which benefit from easier microUSB access by facing forward rather than upwards. Oh, and it's also reversible!
bit:commander
4Tronix's bit:commander packages a combination of accessories into a single unit that fits neatly on the edge connector - including an amplified speaker, power, on/off switch, joystick, analog rotary knob, extra buttons and an array of multicoloured LEDs. There's example code in both MicroPython and makecode/JavaScript to get you started.