I have simple question but i dont know how to implement this. I need to create an app that can get list of available wifi networks and when user click on some network iphone
Technically yes you can get that info. Take a look at this project for example: https://code.google.com/p/iphone-wireless/
However, according to AppStore terms and conditions you are only allowed to get the SSID of the network you are currently connected to but your are not allowed to publish an app that uses private libraries. Take a look at this issue How do I use CaptiveNetwork to get the current WiFi Hotspot Name