Throwing some motors are okay but making them go with the LoadCape is much more sophisticated.
I2C relay UART RS232 optocoupled power supply switching PRU GPIO
Replicape is an open source hardware and software project for bringing 3D printer capabilities to the BeagleBone and BeagleBone Black
BBB, Arduino UNO 5V interface
Affordable plastic BeagleBone Black enclosure
Replace the brain in your LEGO MINDSTORMS EV3 with a BeagleBone Black.
MikroElektronika mikroBus Cape
Antique Podcast Player
External Signal Cape - protecting Your vulnerable BBB IO-Ports by level-conversion and protection elements.
BeagleBone Black SDR cape: software-defined receiver (0-30 MHz), web-controlled, ADC + FPGA + GPS
Turning DNA into Data
BeagleBone Black 0.96" OLED Display 128x64 pixels
Simple, low cost, SDR and RF instrumentation boards
Bone Tagzzz is an RFID cape for beagle bone black with Bluetooth Low Energy support for use as a smart, connected RFID sensor.