Google's YouTube app is all well and good for watching Superman rescue Sandra Bullock, airplane passengers belt out "Circle of Life," and the like. But what if you want to view your favorite clips when there's no Internet (like, say, on an airplane)?
Furthermore, streaming lots of YouTube can quickly chew through your monthly data allotment, meaning unless you're connected to Wi-Fi, you should probably resist the urge to see your favorite "Nashville" song for the trillionth time.
The fix for both issues: Download YouTube clips for offline viewing. Google's own YouTube app doesn't allow this (unless you have a YouTube Red subscription), but at least one iOS app does. Here's how to save YouTube clips to your iPhone.
Update March 24, 2016: The iTube app previously mentioned in this post is no longer available, and the same is true of most other apps that promise YouTube downloads. Fortunately, there are countless desktop and even Web apps that can save videos for offline viewing, but transferring them to your phone or tablet is a hassle. The steps listed below let you sidestep that extra effort.
Step 1: Install Readdle's Documents 5 for iOS. Wait, what? A PDF viewer? Stay with me.
Step 2: Run the app, tap blue compass icon in the lower right corner, type savefromnet into the address bar and then tap Go.
Step 3: Tap the first item in the search results: "The fastest free YouTube Downloader - Savefrom.net."
Step 4: Now you're going to need the URL of the video you want to save. Assuming you were already in the YouTube app when you found the video in question, return to that app, tap the Share icon and then choose Copy Link. Return to Documents 5 and paste it into the URL field. (You also copy a YouTube URL from a Web search or any other source.) Tap the blue arrow to continue.
Step 5: Now you should see a thumbnail of the video followed by a green Download button. Tap it, then follow the prompts to complete the save.
Step 6: In the lower right corner of the screen, tap the Downloads icon. Presto! There's your file. You can view it from within Documents 5, or move it to the Camera Roll. If you want to do that, it's a little tricky: Tap and hold the icon for the downloaded video, then drag it up to the top left corner (where it says "Drag here"). Keep holding until the view switches to a folders screen. Drag the icon to Photos and release.
And that's it!