I need to delete a message from my iPhone w/o going into the app?

So I texted my friend the full chemical name for Titan (longest word in the English Language) and now I can't open the app. So I need to delete the message without going into the app.

Added (1). I fixed it! But if you want some points, I'll pick the most random sentence for best answer. Free points!

Added (2). If anyone in the future wants to know, you do a search for someone else and then go back to the list of convos. And delete the entire convos. With the person.

Just quit the app and try and open it again. Other than that you are screwed

Yo yo yoey
vote for zoey