Sometimes if you need to play a YouTube video but WiFi may not be available. You can download the clip on your iPad as your backup plan.
Step 1: Download the free OPlayer HD Lite
Step 2: Obtain the URL of the YouTube video (watch the video below)
Step 3: On Safari, go to the website (http://video.online-convert.com/convert-video-for-iphone or http://video.online-convert.com/convert-video-for-ipad)
Step 4: Enter the YouTube video URL and state the interval (in HH:MM:SS format) to convert. When the conversion is done, click and hold the “Direct Download Link” and click “Copy”.
Step 5: Open OPlayer HD Lite -> Click on the browser -> Paste the copied link from step 4 -> Select “Download the file”
OPlayer HD Lite (Free)