These example Arduino sketches are modified versions of the examples included in the Arduino IDE after the ESP8266 Board is added in Arduino Board Manager.
The Ardiuno IDE can be downloaded from: https://www.arduino.cc/en/Main/Software
The slides used at the August 2015 meeting of "Internet of Things (IoT) Orlando" meetup hosted by Factur (http://factur.org) can be viewed here: https://docs.google.com/presentation/d/19mj6slnVKwWWF5lyO0aNDqd4mb5NBi6Zr_ZhWUY1mCk/edit?usp=sharing
For setting up the Arduino IDE, refer to the ESP8266 Arduino github: https://github.com/esp8266/Arduino