Slab Guard: A verification app checks slab serial numbers against grading company databases before you buy, exposing cracked-and-reslabbed fakes.

Support PSA cert verification first as a free tool and add scan-at-show mode plus seller history for a premium tier.

Why it can work: Cracked-and-reslabbed fakes exploit serial numbers; verification against grader databases is cheap to build and protects the highest-value transactions.