Counter-Strike Portable is a free, unofficial Android version of Counter-Strike: the very famous multi-player FPS that so many of us have played on our PCs. It requires an Internet connection, unless you play against the cell phone.
How to install Counter-Strike Portable
To install Counter-Strike Portable on your cell phone, download the APK file and copy it to the memory on your phone. Then, run the file from Astro File Manager or another similar file manager. Remember to have the Unknown sources option checked in Settings>Applications.
Grab your AK-47 and leap into the fray!
Once it is installed and run, Counter-Strike Portable will show you the servers available for playing online. Select one and press Autojoin so that the game chooses the side for you. As you earn money, you will be able to choose other roles, like SWAT or doctor.
It is better to play Counter-Strike Portable with a high-speed Wi-Fi connection, since the lag is significant with 3G. Furthermore, many of the Counter-Strike Portable servers are located in Russia and other distant countries, so don't be surprised by connection problems.