: Go to Settings > Security and check the box for "Unknown Sources" to allow the installation of APK files not from the Play Store.
You can find these versions on reputable APK repositories like APKMirror or Aptoide , which host archives of older software. Key Features for Legacy Devices mx player for android 4.1.2
: The HW+ decoder allows the app to use the device's hardware to decode video, reducing CPU strain and lag. : Go to Settings > Security and check