Android Kit Applications. Mac, Windows or Android are the typical operating systems installed on smart phones which have popular currently. Android is the most preferred app by smart phone users. Since Android is an open source platform, any manufacturer can install it on their phones. The cost of production has, therefore, gown down due to the availability of the free OS. Many applications are being developed today, and those generated by Android are known as the android application. When an app is fully developed it can carry a variety of files and folders. The files and folders define the capabilities of the app. For one to be able to operate the app on the cell phone, they need to create an archive that has all the necessities. Android package kit is the term used for the archive file. APK is a full package that contains all the data and files that are required to run an app on a cell phone device. It comprises of a source code that defines the functionalities of the app. Classes.index is the technical term for the source code. Manifest file is the other component of the APK. Provisions of specifications for permission to the application’s needs, package, it’s flow, signatures, certificates, version codes and SHA-1 Digest are some of the functionalities of the component. The other component is referred to as libs. The element comprises jar files and codes which act as library for the application. The asset component has a directory that files texts, fonts and audio. The layout for the various pages of the app are determined by a component known as resources. Other directories contained in the kit includes META-INF and res. Development of an app requires that it is tested before release into the market. Then an export APK is generated where the ones developing it sign in the app with a coded key. This is done to prove of their authority over the application. Users can then access the app in the Google play store after it is uploaded. When one is downloading the app from sources such as Google play store, the APK is the one that is downloaded and installed on the phone. Android Apps can also be accessed from APK MIRROR. Applications found in Google play store can be downloaded in the APK MIRROR. An account is however not required like in the case of Google play. During uploading and downloading of applications, high-security measures are provided so as to provide highly trusted and original apps to the users in the play store. The High-security measures include signature authorization and verification of certificates. APK MIRROR offers the ability to download older versions of an app if one is not satisfied with new one.