Basic Information Concerning APK Applications. Mac, Windows or Android are the typical operating systems installed on smart phones which have popular currently. The commonest OS is the android. The availability of Android as an open source platform has enabled many mobile manufacturers to install it on their gadgets. 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. These define its functionalities and resources. In order for a mobile app to function, an archive with all the necessities is required first. The archived folder is commonly referred to as APK. 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. The APK also comprises of the manifest file. Some of the functions of the component is to provide specifications for permission to the application’s needs, package, it’s flow, signatures, certificates, version codes and SHA-1 Digest. The other component 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 different layout design for android applications are generally defined by the resource component of the APK. Other components of the android application package are META-INF and res directories. Testing of an application has to be carried out during development. Then an export APK is generated where the ones developing it sign in the app with a coded key. The secret code put by the developers acts as a proof of authority over the app. Uploading of the app in to the Google play store is done to allow users download it. The android package kit is the one that gets fitted to the mobile gadget when one downloads the app. Android Apps can also be accessed from APK MIRROR. Applications found in Google play store can be downloaded in the APK MIRROR. Having an account is not a requirement when one is using APK MIRROR to download android apps. Security measures have been put in place by both APK MIRROR and Google to ensure that only original and trusted apps are made available to customers. Some of the security measures include verification of certificates and check of authorization signatures. 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.