If you want to install an application on Windows, we have an .exe file for that. For Mac OS X, we have .dmg files. In the same way way, have a specific file format for Android phones and tablets that is used to install application on it and it is called an APK file (because it has the extension of .apk).
Step 4: Select a safe folder on your computer and extract the downloaded zipped files to this directly. For example, on Widows 8.1/8/7/XP/Vista, install it on C:/; on Mac or Linux, install in on $HOME/
Step 5: Download the application file (APK) to a folder on your computer. And connect your device to this computer via a USB cable.
Step 6: Open Command Prompt on your computer and type the following: adb install <1>/<2>.apk. When you are typing the command, replace <1> with the path to your APK file and replace <2> with the name of the APK file.
2. Install Android Apps from Google Play
Installing apps on your Android device from Google Play (formerly Android Market) is straightforward. With this way, you don't need to download the APK from computer.
Before starting, make sure you have Internet connection on your device, a Gmail account for logon the Market, and the SD card inserted in the device. Here's how.
Step 1: Go to the Google Play application on your device and login with your Gmail account and password.