Search for "YouTube v12.xx APK" on trusted mirror sites like Enable Unknown Sources: Settings > Security "Unknown Sources" to allow installation from outside the Play Store. Open the downloaded file and tap
To continue watching YouTube on this version, you can use these methods: 1. Use a Web Browser (Recommended) Download Youtube Android 4.4.4
Because you aren't using the Play Store, you need to allow your phone to install apps from third-party sources. Search for "YouTube v12