Since this app is not available on the official Google Play Store, it must be side-loaded as an APK file. Smart YouTube TV (Android 4.2+) APKs - APKMirror
: While the newer "SmartTubeNext" generally requires Android 4.3+, some stable legacy builds are still hosted on APKMirror specifically for Android 4.2+. Smart Youtube Tv Apk Android 4.4 2