This ESP8266 default module that works by AT commands, thanks to the contributions of the community has made integration with Arduino IDE.
This module (ESP8266) integrates the capabilities of an Arduino + Wifi (Ethenet) and easily the perfect combination for more or less one dollar, just personally I use in my applications in industrial integration, this module is perfect.
Installing ESP8266 in Arduino IDE is only valid from version 1.6.4 and above, in my case there are newer versions but I liked the version 1.6.4 and it worked perfect.
Video step by step explanation Installation and configuration Arduino IDE
PDAControl started as a hobby and grew to a more complete testing space and better documentation,
Without considering these useful contributions or simply want to contribute to keep growing - here a link.