Small closed case designed from scratch. No screws or glue needed. If you find it useful, leave a comment – maybe I can prepare also open display version (no thin cover above LEDs) or some holder for standard micro:bit battery pack. ;)
Two parts, 0.2mm (or 0.1) layers, standard 0.4mm nozzle. Print the upper part from clear material (Crystal Clear PLA from Fillamentum did the work in my case) to see the LEDs. You can use multicolour print for more attractive box.