This is simple tutor to make local web sever, that can control LED (through GPIO16) through mobile phone.
You need wifi router, so both ESP12E and mobile phone connected to this wifi router.
Step 1: Upload Firmware
Using arduino IDE to upload firmware for ESP12E
(sorry, i can't post code here, please download the project file)
Step 2: Testing
After upload firmware to ESP12E successful, it will show IP address via Monitor screen. Through this, we can know IP address of ESP12E, this case is 22.214.171.124
Step 3: Control LED
Using mobile phone (connected to wifi), type IP address 192.168.1.98 to Web browsers. It will show local web server of ESP12E, from this, you can control ON/OFF led on GPIO16