I wanted my missed questions back, so I built an app

Studying for an AWS certificate last year, I bought a workbook and worked it cover to cover. Then the book went useless. I wanted the missed questions back, but the answers were already written in.

Around the same time my wife was studying Japanese. Workbooks piled up at home, same story. A page you solved and marked never studies the same twice. The answer reaches your eyes first.

Why missed questions stay missed

Anyone who writes in workbooks knows it. Check marks, corrections, notes in the margin, underlined passages. A touched page shows its answers before anything else. Covering them up barely works — your hand remembers where everything sat.

The options were thin. Buy the same book again, hide answers behind a cover card, or copy missed questions into a notebook by hand. Copying ate time, and check marks peeking past the cover still interfered. Above all, gathering just the missed questions into one set was itself the chore.

New books weren’t the problem — marked pages were

A fresh copy fixes it until you miss again. There was no way to keep only the questions worth a second pass.

So I built an app that photographs a page and restores it as a clean question. Take a photo of a marked-up textbook page and it comes back like a question you have never seen — circled answers and scribbled notes gone. It re-typesets the text rather than retouching the photo, so no trace of the answer survives.

What you collect sorts into Folders and Tags. Then filters pick the set: missed only, untried only, Bookmarked only. Stuck on one? An AI explanation sits right beside the question. Any set prints as your own paper test. Solving runs on the device, so the subway works too. A question added on iPhone continues on iPad.

For adults who write in their workbooks

If you are preparing for a professional certificate or a language test with a pen in hand, the situation matches. A solved book is too good to throw away and too spoiled to solve again.

I finished my AWS study this way, and my wife works her Japanese books the same way. It turned out not to be just our house’s problem — certificates led among the first week’s users.

Grab it from the intro page or the App Store.

I built it to study with, so it has rough edges — but that also means it gets fixed daily. Send complaints and ideas to support@hyunsanglabs.com. It genuinely helps.