This article explains how to save YouTube videos to your camera roll. Instructions apply to iOS and Android devices.

To save YouTube videos to your iPhone, iPad, or iPod touch's Camera Roll for offline viewing, you'll need to install Documents by Readdle. This app has a built-in web browser that can save video files to your device, something that regular iOS web browser apps can't do.

Download, install and open Documents by Readdle.

Tap the compass icon in the lower right corner of the screen.