I am a person that often forgets to hit the send button when texting...and i also read messages and then quickly forget about them. Both of these have gotten me into trouble with various people. It would be nice to have a notification or settings to flag particular people/conversations with:

1) you havent sent this message (been a draft for x amount of time)
2) you have not replied to the last message that (insert person you flagged here) has sent you.