Friendship Lights
These lights are a matched pair which were made for a friend who wanted to stay connected to someone who was moving away (both their names begin with the letter K).
When you press the button on one, the other lights up to let your friend know you're thinking about them.
I made them using a pair of Adafruit Feather HUZZAH's with ESP8266. They use WiFi to connect over the internet through IFTTT.
The case was made of layers of lasercut MDF glued together and topped with etched acrylic to give a diffuse glow to the LEDs inside.