Lex Kravitz has designed a simple board containing the ULN2003 stepper motor driver in a Feather form factor:
This Feather Wing was made to be hand assembled with through-hole components, which I find easier to put together in small runs. In the future I may make a version with SMD components as well for professional manufacture. I made this to control 5V 28BYJ-48 steppers that are easily available for ~$2-3 each. Often they come with a ULN2003 driver board, if you are thrifty you can grab the chip off the board and move it to this board saving ~50 cents per board.
This board contains:
1) Two 3-pin headers (GND, PWR, and SIG). These can be used to control a servo or additional sensor.
2) A 3.5mm TRRS port for external control
3) Two LEDs tied to digital pins
4) The ULN2003 motor driver
5) Two small buttons for user control