http://www.messletters.com/en/ Wasn't that easy to find, as it's a hard thing to phrase for Google. The third one is what does this. I'm sure there are better sites, but that's the first I found.
For my own future reference, it is apparently called "Full width text"
http://www.messletters.com/en/ Wasn't that easy to find, as it's a hard thing to phrase for Google.