Virtual Private Network or VPN application is used for security reasons to hide your IP address as you are using Wi-Fi in public place like Airport, Restaurants as through IP address your current location can be figured out. VPN apps are also used to open banned or blocked sites in your country like YouTube is banned in Pakistan and in many Muslim countries. In China, many people use VPN because Chinese Government has filtered out many sites. VPN assigns you an IP of a different country to open a particular site. VPNs can also be preferred when you want to stay anonymous on the web.
There are hundereds of free VPN apps on Android but following 3 are the best of my knowledge. You can use these app’s by downloading it from the android market, open the app and hit connect your app will be activated.
Hotspot Shield gives you a fast VPN connection but it own performance on Android is slow app as it has too many ads running on it.
Hideman VPN app is a good app and it’s much faster then Hotspot Shield at the moment.
Orbot app only runs on android which are rooted.
If you know a better free VPN app, please tell us in the comments.