Our Alteryx users get together every other week to work on a challenge together, and this is our pick this week! Looking forward to reviewing this one with my colleagues.
My solution is the same as many others.
This was great practice for me to experiment more with apps and interface tools. It took me a while to figure out how to get it to work for successive runs of the app (ie how to make sure previous values weren't being used). I also did the extra credit and checked for not having 3 check boxes selected.