The
Library Books app, by Harold Chu. You give it your library card numbers and PINs, and it keeps track of when items are due, hold requests are filled, etc. Menu bar icon is a book and a number, with the book changing color to indicate that something is due, and the number is the number of items outstanding. Nice little app, plays with lots of different library catalog systems. The three of us are enthusiastic users of our local libraries, and this is a pretty painless way to keep track of our numerous borrowings.