Debugging web applications using IDEs or Web Browser extensions.
Debugging mobile applications is harder and this is where web debugging proxies come in hand.
Fiddler (http://www.telerik.com/fiddler) is a nice free app that can help here.
From Fiddler side you have to be sure that you check «Allow remote computers to connect» from menu Tools -> Fiddler Options and Connections Tab.
On the client side (in our case an Android device) from Network Connections(Wi-Fi), long-press the connected Network then Modify and on Advanced Options enter the Proxy hostname and Proxy port (default on Fiddler is 8888).
Just for testing try to open a web page from Chrome and you will see on Fiddler the traffic.