The code is made for a 14 * 14 matrix using WS2812, but it should work for other sizes and LEDs by changing Rows, Columns and WS2812 in "RGB_LED_matrix.ino". Some of the animations were found on other github pages, and are modified to work here. Links to the original code can be found in "Animations.h" and in the Animations section down under.
Go to File>Preferences>Addittional Boards Manager URLs
copy and paste http://arduino.esp8266.com/stable/package_esp8266com_index.json
Go to Tools>Board>Boards Manager
Search "esp8266" and install version 2.7.4. This program has not been tested on later versions.
Go to Tools>Board>ESP8266 Boards
Chose "NodeMCU 1.0 (ESP-12E Module)"
FastLED
Adafruit Neomatrix
Adafruit GFX Library
Adafruit Neopixel
Found on https://github.com/FastLED/FastLED/blob/master/examples/XYMatrix/XYMatrix.ino
Found on https://github.com/atuline/FastLED-Demos/blob/master/confetti_pal/confetti_pal.ino
Found on https://gist.github.com/StefanPetrick/1ba4584e534ba99ca259c1103754e4c5
Found on https://github.com/atuline/FastLED-Demos/blob/master/dot_beat/dot_beat.ino
