ErrorBank: Mistake Notebook, a study app for iPhone and iPad, is listed as free on the App Store. The tech site New Mobile Life reports that the app normally costs US $0.99 and is free for a limited time. The App Store listing shows the price as Free but does not give an end date for the offer, so it can end at any time.

What does the app do?

ErrorBank is built around one idea: keep the questions you got wrong or could not solve, and practise them again until they stick. According to the developer, Ibrahim Akcay, it is not a question bank or an automatic solver, and it is not affiliated with any exam organization. The questions in it are your own.

The listing describes these features:

  • Snap a question with the camera or import an image, then crop it and tag it by subject, topic and difficulty.
  • Search and filters to find a saved question quickly.
  • Write or draw on a question or on a blank page, by touch on iPhone or with Apple Pencil on compatible iPad.
  • Smart Review, which brings each question back at a time based on how well you know it.
  • A goal of 1 to 10 correct solves for each question. The developer says every success pushes the next review further out, tough questions return sooner, and a miss never erases your progress.
  • Subjects, topics and tags, with counts of solved and open questions so you can see where mistakes pile up.
  • Accuracy, session results, daily stats, study streaks and reminders when questions are due.
  • Sharing questions or exporting them as a PDF.

The app works offline. On privacy, the developer says there is no account, no ads and no tracking, and that photos, notes and drawings stay on your device. The listing also states that the developer does not collect any data, though Apple notes that this information is supplied by the developer and has not been verified by Apple.

How do I get it?

  1. Open the App Store on an iPhone or iPad and search for “ErrorBank: Mistake Notebook”, or open the listing from the New Mobile Life article.
  2. Check that the price button reads Get rather than a price, and that the developer is Ibrahim Akcay.
  3. Tap Get and confirm with your Apple account, as you would for any free app.

Once you have downloaded it, the app stays in your Apple account’s purchase history. The listing says it requires iOS 26.5 or later on iPhone, iPadOS 26.5 or later on iPad, and visionOS 26.5 or later on Apple Vision. No Mac version is listed, and the app is 24.7 MB. The interface language is English plus 38 more languages, including French, Spanish, Japanese, Korean, Traditional Chinese, Simplified Chinese and Vietnamese.

Who it suits

ErrorBank is aimed at students preparing for entrance and national exams, high school students who want to stop repeating the same mistakes, and anyone who learns best by solving problems. It fits people who already work from past papers or textbooks and want one place to collect the questions they missed.

What are the catches?

The original price of US $0.99 comes from the tip article, not from the App Store listing, which only shows the current price of Free. No end date is stated, so the offer can end at any time and the price shown when you open the page is the one that counts. The listing says there is no automatic sync between iPhone and iPad, so questions saved on one device will not appear on the other. The app also has not yet received enough ratings or reviews on the App Store to show an overview, which means there is little outside feedback to go on. The required iOS version is recent, so older devices may not be able to install it.

If it suits you, open the App Store listing and download it while the price shows Free.