Save videos to your iPhone for offline viewing

Download YouTube clips for offline viewing. Google’s own YouTube app doesn’t allow this, but at least one iOS app does. Here’s CNET’S guideline to save YouTube clips to your iPhone.
Step one: Install iTube. It’s a free YouTube player, though if you want to remove ads, it’ll cost you 99 cents via an in-app purchase.
Step two: Browse or search YouTube for a video you want to save, then start it playing.
Step three: In the top-right corner, tap the little floppy-disk icon — which is easy to identify because it bounces. (You may also see a somewhat misleading “Preload to Cache” label, which appears to be developer-speak for “Save to iPhone.”)
Step four: For some videos you may have the option of selecting a resolution. Either way, tap Done. That starts the download process.
Step five: Tap the Cache icon and you’ll see your saved video(s). Tap any one of them to play it — no Internet connection required.
By the way, iTube lets you sign into your Google account (More > Account > Sign in) if you want to retrieve and save videos from your own playlists.