I used part of the "Laundry App UI Kit Sketch Resource" design that was designed by Satheesh Kumar at: https://www.sketchappsources.com/free-source/3397-laundry-app-ui-kit-sketch-freebie-resource.html to create a quick prototype

Lets babies mix and match and make all kinds of silly halloween characters. Images from: https://www.comofazeremcasa.net/brinquedo-com-blocos-de-madeira-para-criancas-com-moldes/

A basic mockup of a sign-up/sign in screens along with a 2-way authentication of a uniquely generated code each time.