Yesterday I accidentally learned that you can reposition the closed captions on YouTube videos. I waa at the Smartboard talking about how the cursor and my finger were a couple of inches apart, and I accidentally dragged the captions of a YouTube video that we were watching.
I was looking at someone’s photos on an iPhone and we both discovered you could cut parts of the image out with a long press and drag (IIRC.)
You can make them into stickers and put them into messages, can even have them moving. That stuff was an advertised feature though.