For example, if you download a movie in the Netflix app, that movie can only be viewed in the Netflix app, because that's the only app that can open Netflix files. If you download a WebM file from ...

Do the following to find the downloads on your device: Several Android file manager apps on the Google Play Store allow you ...

It usually occurs when the file is downloaded from a not-so-popular vendor. You can ignore this warning without worrying much. However, if you wish to disable Open File – Security Warning ...