XAPK is a file format for Android application packages that is used to install Android apps on mobile devices. It is a container file format that incorporates APK and additional associated files required for the installation. The other associated file is an OBB file that stores additional files such as graphics, media files, and app data that are required to keep the application running. XAPK files are not supported by Google Play and are used for distributing on third-party Android app download websites only. XAPK files are compressed using the standard ZIP file format and can be extracted using a standard compression/decompression software such as WinZIP. To install XAPK files, one can use third-party XAPK file installer apps that are available on Google Play Store. However, it is important to note that installing XAPK files from unverified sources can be risky as there might be a chance of hidden malware attack, virus or worst case spyware.