Signaloid C0-microSD is an FPGA development board based on the popular iCE40 FPGA from Lattice Semiconductor in a microSD form factor.
You can use it to prototype your designs on a breadboard using a microSD breakout board or integrate it into your new PCB designs by adding a dedicated microSD slot, using the available pins as GPIO. You can even plug the Signaloid C0-microSD into an existing platform that supports microSD cards (like the Bee Data Logger or the Adafruit Adalogger) and use it as a co-processor.