A ‘Vesper’ is a cocktail drink that was introduced in Ian Fleming’s novel ‘Casino Royale’. John Gruber is a fan of the James Bond stories and of high alcoholic beverages. I don’t see how the name has anything to do with note-taking, though.

http://en.wikipedia.org/wiki/Vesper_(cocktail)

There's more info on the appstore:

Collect your thoughts.

Vesper is a simple and elegant tool for collecting notes, ideas, things to do — anything you want to remember. Use tags to group related items into playlist-like collections. Vesper imposes no system; organize and curate your notes whatever way comes naturally to you. Eschewing complications, Vesper's focus is on how it feels to use it.

• Attach photos to notes.

• Use drag-and-drop to reorder items. Move important ones up, inessential ones down.

• When you’re done with an item, swipe it to send it into the archive. Out of sight, but remembered forever.

https://itunes.apple.com/us/app/vesper/id655895325

I was disappointed, as well. Looking forward to reading more about vesperapp. (I've just set up a Google Alerts for it).

Vesper means evening or evening prayer