The Glowtie is based on the ESP-12F ESP8266 module, which controls lighting animations for the WS2812B LEDs (Neopixels).
The ESP hosts an Access Point network with a site that you can use to control the patterns and colors of the lights.
The main PCB has all SMT components soldered on the front, with pads on the back for two 1S 300mAh lipo batteries wired in parallel. A 3D printed bracket is then glued onto the back, housing the batteries and providing the button slot. An optional cover can be press-fit over the PCB for a more clean look.
All production KiCad files, firmware, and 3D models are available on the Github page!