Whatsapp Message Analysis
This tool processes your conversation log from WhatsApp to give you some interesting insights, see the bottom of the page for help. It is all processed locally in JavaScript, so your messages are perfectly safe :) That said, JavaScript is a bit slow, so it may take a while. You may examine the source code here, be kind it is poorly optimised.
Pocket-RC4
Pocket-RC4 is an adaptation of the RC4B algorithm for use with standard playing cards, developed by Matthew E. McKague in his master’s thesis.