Invisible iOS Dock Spacer Icon

Read these instructions from _DavidSmith and then come back to this page and follow them.

(in short: tap the Add to Home Screen button from the little icon at the bottom of Safari that looks like an arrow coming up out of a rectangle)

and you'll end up with a grey icon on your iOS home screen you can use to space out your dock, so this:

becomes this:

Ahhh.