A Guide to Free Apk Downloads. 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. 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. 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. Runnning an app in a mobile phone requires some special data and files that are found in an android package kit. The package kit has a code that determines its capabilities and functions. The other name for the source code is the classes.index. Android package has another component known as the manifest. 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. Libs is the other vital component for the APK. The element comprises jar files and codes which act as library for the application. Asset is the other element of APK and performs the functions of filing fonts, audios, and texts. The resources component is the element which defines the layout for the various pages of the app. 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. A secret key code is then used to sign in the application. The secret code put by the developers acts as a proof of authority over the app. 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. APK MIRROR is the other online platform that provides clients to access android apps. 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. High security measures are provided so as to provide highly trusted and original apps to the users in the play store during uploading and downloading of apps. 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.