Spy Pix is an steganographic tool to hide images inside others, the advantage over encryption is that while encrypted data indicates something of value being protected, by hiding data in plain sight an attacker would have to know first what he is looking for. This tool can be used to send secret messages to your friends, they will need to have SpyPix installed to reveal the hidden message.
The images are saved as .png (Portable Network Graphics), they could be uploaded to flickr or photobucket and your contact download it from anywhere in the world to decode it, the hidden image can contain a written message with instructions. This system avoids compromising your contacts, if your iPhone is seized by hostile authorities they could work out who you have been emailing with and follow the trail, uploading the image to a public website with thousands of visitors needs some guess work to find out who the receiver is.
Supporting for the built-in camera Spy Pix can use photographs you take as a carrier to hide other images, use a photo from your album or copy an image from another app, the photos can be easily blended using a slider that allows you to control end image quality, you can send them by email using a single button, the options aren’t amazing but they do everything you need and keeping it simple makes operating this app easy.
Spy Pix could be greatly improved if encryption was used and a password was asked to decipher the hidden image/message.
Note: This app is not free, priced at $1.