sneaktext 1.0.0 - secure just about any text-based communication you can think of
app store link
from the app description:
Anything you want to know, any US-based bloggers wanting promo codes or anything like that, feel free to post here and I'll get back to you
Sneaktext is a fun little tool designed to secure pretty much any kind of simple text note you can think of. Maybe it's that note you're about to pass across the classroom, or the SMS you're sending to your partner - anything that you don't want anyone else reading except who's supposed to. Share a codeword with your friend, enter the message and the codeword, hit 'sneak it' and the message is transformed into unbreakable* cipher text.
* resultant ciphertext not 100% unbreakable - those with the right resources and enough time will be able to crack it. please be responsible.
Also check out the blog at LtBrenton