Solitaire Cipher

Solitaire Cipher is an implementation of The Solitaire cryptographic algorithm. It was designed by Bruce Schneier "to allow field agents to communicate securely without having to rely on electronics or having to carry incriminating tools." The Solitaire algorithm can be done by hand using a deck of cards or even in your head. Solitaire is designed to be secure even if people knows how the algorithm works. It offers real security, not security through obscurity.
TL;DR A simple yet secure message encryption app that can be done with a deck of cards.

Code is open source. Code can be found on Github here. https://github.com/stequald/Solitaire-Encryption-Android