To encode a message set the "a=" variable to the amount that you want (this scrambles the alphabet) press the "encode" button and enter what you want to encode. If you are going to share your encoded message with someone be sure to include the a= value so they can set the variable to the right amount. If you try to decode the message with out the right value it will come out as a bunch of gibberish. To decode a message press the "decode" button and enter the code, again be sure to have the a= value set to the correct amount when decoding.
This project contains 195 blocks of code and is a deep dive into the use of lists on scratch.