Since Android 4.4.3 is an older OS, you need a compatible version. SmartTube (Official Site) or trusted mirrors like to find legacy versions that support Android 4.2+. Stable Release Code : If using the "Downloader" app on your TV, enter code Install the App Open your "File Manager" or "Downloads" folder. Select the downloaded APK file and click
: Use a browser on your TV or a PC to download the correct legacy version (often tagged as "4.0+") from reputable sources like the Smart YouTube TV (Android 4.0+) variant on APKMirror Transfer and Install
: Go to Settings > Security on your device and toggle on "Install apps from unknown sources" .
: The latest stable versions of SmartTube (e.g., v31.xx) continue to support Android 4.3+ . Where to Download