This app/shortcut opens directly the settings app of mobile network settings to switch between "2G" and "allow 3G" networks (e.g. to save battery). A direct switch is sadly not possible.
It places also a shortcut in the statusbar to reach the settings from everywhere.
Tags: how to change mobile network type in , 2g network , switch network type 2g / 3g , switch network type , change network type , change mobile network type