A free simple widget(1x1) to change the ringer mode to Normal, Silent and Vibrate mode in 1-click and also you can switch on/off your WiFi.
You can choose any ringer mode in just one click i.e. no need to go through other ringer modes.
It is a widget not an app. You can add this widget on your home screen using two methods:
Method1:- Menu -> Add -> Widgets -> Quick Modes
Method2:- Long tap on an empty space of home screen -> Widgets -> Quick Modes