Following is a simple example on how to wire a led or a push-button..
We used just two lines in this example but more lines are available and every one is configurable either in input or output mode: see the WiFIG25 pinout.
To learn how to drive the led or read the push-button state visit this article: GPIO lines.
All the lines are at 3.3 Volt. Do not connect any 5 Volt logic level signals to avoid damages.