it's basically the #Penghicorn  badge with SD card slot. I/We should do this in KiCad. Needs to feel like a Multimeter, a Game Boy and a Tricorder had a good time once.

IO and serial programmer

something like an atmega32u4 (or less) or a SAMD21 (or less) might make sense to be the programmer for the ESP8266 and also take over some peripheral tasks, like scanning buttons, IR?, light sensors? reading battery voltage etc. A seeed studio grove connector or something similar (qwiik, SAO connector...)