Tutorial: How to install applications on Android using Apk files

The option of installing programs via. apk is useful because, besides there is no need to pursue the program in the Android Market, you can download it on your computer and send it to the phone via USB, when you want. Without the need to spend a data plan 3G.

Step by step

1. Look for ASTRO File Manager in the Android Market, through the smartphone. Then click Install. This program is basic to any device with Android, as it allows you to manage files on the memory card in a similar way to Windows Explorer. 
2. Then download the file. apk on your computer. Connect the device to the machine and transfer the file. apk to the memory card from your phone. We recommend creating a specific folder for this file type. 
3.  Unplug the USB cable and open the File Manager application ASTRO. Look for the folder you created and click on the file. apk. Select "Open App Manager " (Open Application Manager) and then click "Install ".

      4. Enjoy your new application.

Source: Baixaki