The App Hub

(A Curated Hub of Useful & Fun Apps)

My Soduku (3D 4 by 4 Hypercube)

Quick Guide: Enter digits 1 through 4. Every row, column (in each $4\times4$ layer), 2x2 sub-box, and vertical depth slot across all 4 layers must contain unique values from 1 to 4. Good luck!