A: An XAPK is a compressed package that contains the APK file and additional data files (like OBB files) for larger games. To install an XAPK, you need a dedicated XAPK installer app. You can find legitimate ones on Uptodown itself.
It allows you to download games that might not be available in your local Google Play Store. How to Download and Install Lab Rats APK lab rats apk uptodown
No – but with a caveat.