One great feature of iMessage is the ability to send read receipts to people who send you a text from an iOS device, basically letting them now that not only you have received their text, but you've actually read it too.
But what if, from time to time, you do not want the other person to know that you have read their message right away? Of course, you could turn off reader receipts altogether, but if you're looking for a little more flexibility, have a look at TypeRead...