Trinket is a very small (10 pins) microcontroller board made by Adafruit, originally using an ATtiny85 microcontroller and a bootloader that allowed programming it over USB. It's perfect for all those projects that just need a pin or two and some simple logic, especially when they need to be physically small. Of course due to very limited resources, you had to program it in C (or Arduino).
Recently Adafruit released a new version of this board, sporting an ARM Cortex-M0 microcontroller running CircuitPython. It's the same size and form-factor as the old Trinket, but now you can simply program it by editing the Python files on the USB disk that appears when you plug it in. It's the smallest development board available that runs Python, and it's super-easy to use. I fell in love from the first sight with it.
However, searching the Internet, I couldn't find any add-on boards for it, except for one, that adds LiPO battery charging to it. I have been making some add-ons for the D1 Mini, so far the smallest Python-enabled development board on the market, and now that there is a smaller board available, I decided to make some add-ons for it too.
I already started this with the #Trinket M0 TFT, but as I worked on it, I realized that I will need a lot more shields. I will need one that adds buttons that can be used with that display, and I will need one that lets me control hobby servos. One that offers more analog pins would be nice too, and perhaps even something that enables wireless communication of some kind. They should all be tiny -- fitting in a one square inch, preferably the size of the trinket itself -- and they should be stackable as much as possible.