Android Kit Applications. Smart phones currently nowadays have become very popular and come with a variety of operating systems such as windows, Mac or Android. The most popular is the android. Since Android is an open source platform, any manufacturer can install it on their phones. This has made the cost of the devices less than making their operating system or using one that is paid. Various apps are coming up every day, but the most common ones are the android apps. Each of the application when complete can carry different files and folders. The features of an app are determined by the files and folders it carries. 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. Runnning an app in a mobile phone requires some special data and files that are found in an android package kit. It comprises of a source code that defines the functionalities of the app. It is generally referred to as classes.dex. Android package has another component known as the manifest. The component provides specifications for permission to the application’s needs, package, it’s flow, signatures, certificates, version codes and SHA-1 Digest. Another important component of the apk is referred to as libs. Lib is a directory that stores information for the application through jar files or codes. Texts, audios, and fonts are stored in the APK component known as the asset. The layout for the various pages of the app are determined by a component known as resources. The kit also contains res and META-INF directories. Testing of an application has to be carried out during development. The developers of the app generate an export app where they sign in the application with secret code. This is done to prove of their authority over the application. Uploading of the app in to the Google play store is done to allow users download it. 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. It, however, does not require one to have an account. 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. Authorization of signatures and verification of certificates are some of the security measures. One of the features provided by the APK MIRROR is the ability to provide older versions of the app if one is not satisfied with the new one.