About a year ago there was a thread here about a card centering calculator app and basically the entire comment section was just people bumping for Android for months lol
So... I built one. It's on Android, iOS, and works in the browser too if you just want to try it without downloading anything.
Been working on it in my spare time for about a year and a half now. No marketing, no budget, just people finding it and sharing it. Hit 1,500 users recently which honestly still doesn't feel real.
It uses AI to detect your card edges and place the centering lines automatically - you can nudge them if needed. Spits out grade ceilings for PSA, BGS, SGC, CGC, ACE, TAG and Get Graded, front and back combined. Free to start!
Best feeling is when someone says they nearly skipped submitting a card, ran it through CardCenter, and it came back exactly what the tool said. That's kind of the whole point, not to replace grading, just to stop people dropping £20 on a card that was never going to hit.
Android: play.cardcenter.pro iOS: cardcenter.pro
Happy to answer anything. Honestly the feedback from people who actually submit cards is the most useful thing I get.