What is an APK file and how to open it?

All the file systems used to install software or a tool on various platforms have extensions according to their types. All extensions indicate the purpose and nature of these files. One of those types of file systems is the APK (Android Application Package) system. Like the .exe file system, this system too relies on extracting the file contents and doing user-defined tasks. Packages get developed in many varieties, like games, tools, utilities, and many more. Popularly known as the “Apps.” There are many advantages of this system as compared to other systems on various platforms.

The idea of "packing" an application for distribution outside the official marketplace has been around almost since the release of SDK (software development kit) in the fall of 2009. The concept didn't have a name until after CyanogenMod 6.0.0 "CyangenMod 6" was released in November 2010. At this time, it became widely known among developers that CyanogenMod 6.0.0 would "pack" their apps upon installation. The name stuck, and thus this technology has become known ever since as "APK packing".

Android application packages also play a crucial role in the application life cycle. From start to finish, the ease of use is the biggest advantage of this system. The second type of APK file usually refers to a compressed archive containing certain resources such as user interface files, icons, images, folders, and other resources needed by the application to run successfully on its target computing platform.

Importance of Java

Any Java application has two distinct types of files: Java source code (.java), and resource files (.ri, .res). The Android phone and embedded operating system assigns the file extension ".apk" for the compressed collection of these two file types. Therefore, the Android application package format is another version of the .zip or .7 file system used to bundle the various assets into one big entity. That way, extraction becomes easier when the number and size of the assets are relatively high.

What is an APK file?

So, what is an app package file? It's the Android operating system's version of a .zip file. It contains all the resources an app needs to run, including its Java code, native libraries, assets, manifest file, resource files, etc. The APK file format was created, so developers could deliver software to devices in a single compressed file. All the user-oriented programs on smart Android devices use APK files.

Properly called, an APK package is a program package that contains the compiled application project. Byte code for this application is generated when the programmer compiles the project in Android Studio IDE. The generated .apk extension file contains byte code along with other resources which are required to execute the application on mobile and embedded devices. The .apk extensions can be opened in any zip archive tool which supports extracting the directory structure of the file.

What does the Android application package stand for?

Android software package files, otherwise known as APKs, are compressed archives of executable code. The archive contains everything an app does, from its GUI and logic to any images it uses. APKs are kept as small as possible, as they must be downloaded over slow cellular networks and unpacked on devices with limited storage. They can be installed on mobile devices with a single click or tap, which makes them convenient to use.

Why do we use APK files?

On personal devices

One could wonder why we use Android application package files when it would be far more convenient to directly install app zip packages. The answer is security. If an app could write whatever it wanted to the SD card, it could theoretically open a tunnel to your PC (if your PC had Linux on it) using whatever communications channel was available, and run code on your PC as if it were on a local network connection.

On embedded systems

The world of embedded systems is full of mechatronic magic and possibilities. The combination of servo motors, Bluetooth, Wi-Fi, and sensors can build things that can talk and walk on predefined commands. The biggest advantage of the Android application package file system combined with an embedded system is UI (user interface). Any screen or display can act as a UI to control the functionality of the embedded system,

How to open an APK file?

For users

Open the file from the download folder and extract it using WinZip or .7 extractor. Or, if you simply want to use the content of the file after executing them, click on it and install the package. These steps work on any platform that supports .zip or .7 file-formats, irrespective of the compatibility.

For developers

Developers can use Android Studio to open or even edit the code inside an APK. If the purpose is not debugging or evaluating the script, then it’s best to use simple extractors or installers.

How to open APK files on Android?

You may also use a file manager app to explore the external storage, and then you can access this file and open it. There are various other different types available in APK files, which you can check on the official marketplaces. Users can also use WinZip or other apps to extract the content of an APK file.

How to open Android application package files on iOS?

iFunbox is a native app for iOS, which allows seamless access to the iOS file system. iFunBox users can easily access APK files on their iOS devices. All you need to do is install it on your iPhone, iPad, or Mac. Please check Apple’s guidelines before using such apps.

How to install Android application package files on Windows?

The first step is to download and create a folder on your Windows OS for the Android application package files. The second step is to download the Android application package file. You can click on the download link using your browser or save it to your PC with a program such as Download Master (free). The next step is to copy the APK file into the folder you have previously created. Double-click to install the file. As mentioned before, this process is often done on a smartphone, so you will need a Google account to complete it on your machine.

How to extract APK files?

Users have the option of downloading verified tools like WinZip, which allows you to extract the files using the same process as you would use to extract any other type of file. WinZip is available both for phone and PC, allowing you to extract the files from any app. 

Although APKs can be obtained from the Google Play Store, there are several reasons why you may need to extract APKs from applications that you have installed on your device. One reason you may need to extract an APK is for doing independent research on an application and its code. Regardless of your purpose, you will probably encounter problems trying to directly convert an APK file on your device to a ZIP or RAR format on your workstation. There are many reasons for this, ranging from unsupported file types on some versions of Android.

Summary

Android application package or APK is a versatile file format that consists of an archive, manifest, resources, native libraries, and more. It would be close to impossible for you to predict the list of contents in this package before it is installed. However, the online marketplace will check whether an application submitted belongs to any Android application package already present in the market before accepting or rejecting its upload. APKs are specially made for use in Android OS and make the lives of users and developers much easier.