One big difference between the Mac and iOS is that, on the Mac, open tabs stay open (more or less1), whereas on the iPad and iPhone, switching away to another app, or even another browser tab, can mean disaster. iOS dumps all those Safari tabs, and they must reload when you return.
For partially watched YouTube videos, this means you automatically go back to the beginning. But what if there was a way to force Safari to remember your watching progress, and reload the page to the exact spot you left off? There is now! I got sick of losing my spot in videos, so I made a bookmarklet that will save your current spot in a YouTube video. Even if you reboot your iPhone or iPad, it’ll reload in the exact same spot.