How to move Iphone icons on screen

You can't undo it, per se. You have to hold an icon until they jiggle again and then reorder them.

You just move them back to where you want. Once you're happy, just press the bottom home button.

To let you know that you can move them. They only jiggle if you press your finger on them for over a second.

Note that you can not only reorder them, you can move them from one screen to another. Hold the moving icon and move it as far right as you can and it will pop over to the next screen.

I got rid of the annoying stock widget and wifi iTunes widgets that way where they will permanently be banished.

I actually use both of those daily 🙂

As for the YouTube widget, it has gone to the 3rd page of no return...