One of the features I like about the Si Stebbins stack is that if you know the bottom card you can calculate the position of any other card in the deck using some “simple” math. Technically the math is simple, but it takes some practice. So I wrote a web page and also an Android app for my phone to help me train in the calculations.
The web version is at http://robertjwallace.com/stebbins and I have an android apk file that I used to install the app on my Android phone. If anyone wants that file I can provide it, along with the source code, and instructions on how to install it.
Basically all the web page/app does is randomly choose the target card and the bottom card. You then have to calculate the position, from the top of the deck, where the target card is. I wrote a blog post explaining the calculation.
You enter your guess, a number between 1 and 52 and the program tells you if you are correct. If you are incorrect the program displays the steps so you can see where you made your mistake.
Pretty straight forward. For those who are interested, I used Google Gemini to write the program and Cordova on a Linux Desktop to turn it into an app.