Yes, 鬼滅の刃クイズ診断アプリ（きめつのやいば） follows the Google Play content guidelines to ensure safe use on your Android device.

A file with .xapk extension is a compressed package file. It is a container file format that incorporates APK and additional associated files required for the installation. The XAPK format was introduced to package the APK file and OBB file together for a seamless delivery and installation process. XAPK format can help reduce the package size of application. On mobile phones, users need to install the XAPK installer first, and then install XAPK files through that installer. You can find the installer here:https://apkcombo.com/how-to-install/. But on PC client, you just need to put the file on LDPlayer.

Yes, you can play 鬼滅の刃クイズ診断アプリ（きめつのやいば） on your computer by installing LDPlayer, an Android emulator. After installing LDPlayer, simply drag and drop the downloaded APK file into the emulator to start playing 鬼滅の刃クイズ診断アプリ（きめつのやいば） on PC. Alternatively, you can open the emulator, search for the game or app you want to play, and install it from there.