These often inject ads or malware. Use the official VideoLAN archive or F-Droid.
Android apps (.apk) are inherently "portable" in that they are self-contained installers, but they must be installed to the system to run; they do not typically run directly from a USB stick without installation. Do you need help identifying your device's architecture (ARMv7 vs ARMv8) to pick the right file? VLC download for android 4.4.2 (KitKat)
