In this project we used a ESP8266 to control a Robotic Arm through Alexa's voice command. Our main goal was to use Alexa as a intermediate to make our robotic arm play checkers. All the checker's code and movements was already done by another group, we just estabilished the communication between robot and alexa. The API used for this achievement was the Sinric's API for Arduino.
For more information, check out the video below or, if you're a portuguese speaker, you can read the documentation of the project in the 'Documents' folder. Thanks.