APK, or Android Application Package, is the file format used to distribute and install application software and middleware onto the Google Android operating system and certain other operating systems, such as Blackberry 9900 Devices with the OS version 7.1.0 or higher.. An APK file contains all the necessary files for a single Android program. APK files are saved in a compressed ZIP format and can be opened with any decompression tool. APK files are essentially a type of archive file, where the format of the packages are based on the JAR file format, with .apk as the filename extension. To make an APK file the software for Android is initially compiled, and then all of its parts are packaged into one file. An APK file contains all of that program’s code (such as .dex files), resources, assets, certificates, and manifest file.
The apps come as APK files so that they could be installed on an Android device. Now the thing is, unlike the .exe and .dmg files, these files cannot be installed directly, and we will have to make some arrangements on our Android device first. So let’s see how can you install these APK files manually when you get one someday.
First of all, we will have to enable the option to install the applications from unknown source on our Android. Open your Android system settings and click on Applications (Programs for some of the HTC devices) and check the option Unknown source. Those of you who are on Android ICS 4.0 you will find these settings under the security settings. On most of the devices, you can now simply click on the file using any of the file managers to install them, using the built-in package manager. If your device does not have a package installer by default, you can download and install an APK installer application from Google Play.
You must find an APK file that you want. Search online for an APK file and download it to an easy-to-find location on your computer (like your desktop). Before you can install it on your phone you will need to make sure that third-party apps are allowed on your device. Go to Menu > Settings > Security > and check “Unknown Sources” to allow your phone to install apps from sources other than the Google Play Store. If you like, you can also download an app like ES File Explorer so you can easily find files on your Android device.
Once you have downloaded the file on your computer, connect your device to it. At this point, you may be asked if you simply want to charge your phone or connect it as a “media device.” Choose “media device”. Then, simply find your phone’s folder on your computer (it will be in “My Computer” or “Computer” on Windows machines) and copy the APK file into a folder of your choice in your Android smartphone.