You can install the Snaptube app directly from your phone's default app store, such as Samsung's Galaxy Store or Xiaomi's Mi Store. Snaptube is not available on the Play Store due to its restrictions on video downloader apps. Alternatively, you can download the Snaptube movie downloader APK file from the official website or trusted APK sites like Uptodown and APKPure. Enable the "install from unknown sources" option in your phone's settings, and then tap on the downloaded APK file to install the app, following the on-screen instructions.