Description:
This is a low cost Arduino-compatible ESP8266 development board.A 1.3OLED display is on the board. It is very easy for beginners. You can program it like Arduino. There is a project support for ESP8266 chip to the Arduino environment:Arduino core for ESP8266 WiFi chip.
Another famous project is NodeMCU, which you can use LUA to control ESP8266. This two projects make ESP8266 spread around the world.

Module:ESP-12F
All ESP8266 pins broken out
12 digital pins write/read/interrupt/pwm/I2C/one-wire supported(except D0) 1 analog input
Integrated 1.3′′ OLED
Micro USB connection
Compatible with Arduino
Compatible with NodeMCU(Lua for ESP8266)

NOTE:
When you use the example of this library:https://github.com/lspoplove/esp8266-oled-ssd1306 Remember change SDA to D1, SCL to D2. and Change SSD1306 to SH1106.
D1 is always connected to OLED's SDA pin.
D2 is always connected to OLED's SCL pin.
Code example has already been put on github.

Document link: https://github.com/squix78/esp8266-oled-ssd1306

Package Included:
1 X NODEMCU ESP8266 1.3’’ OLED
2 X Pin headers