You can make your own cipher tools by learning to programme (and we have a great guide to getting started on the training page) but you don’t need to do that to build a usable cipher tool. You can start with the Caesar shift wheel kit in our official BOSS cryptanalyst handbook. You can upgrade that to work with affine shift ciphers.
You can even build your own Pringle Can Enigma Machine. (Harry designed the first Pringle Can rotor encryption machine in 2005 to help BOSS agents crack a version of the notorious Russian Fialka cipher. We might publish more information about that case in a further training exercise later. For now we refer you to Franklin-Heath who have published full details of how to build a working Enigma machine for use in the field. You will find the instructions at their website. It is no harder to make than a Caesar cipher wheel, though it is a lot harder to use. On the other hand it gives you pretty much the full power of the Enigma cipher for the cost of a tube of Pringles, which is also useful for field rations.)
In the meantime here are some online cipher tools that you might find helpful.
Caesar Cipher Tool
