These instructions describe iOS 1.2. Earlier versions and other platforms may have different features or button names.
How do I add a question?
In Mistake Book, choose Add Question, then Capture Question or Import Question. Crop and prepare the image, choose a folder and writing space, then save it.
Can I save several questions from one photo?
Yes. After capturing or importing a single photo, choose Crop Multiple Questions, either on the check-photo screen or in its full-screen crop editor. Draw a box around each question and use Add Question for another box, up to 20 questions. Select a box or its number to view that question’s preview and adjust its print effect or erasures. During addition, existing boxes become dashed; finishing a new box selects it. Save All saves each question separately in the selected folder. This is manual cropping, not automatic question detection. Importing multiple photos still uses one question per photo.
How do I zoom in while cropping?
Pinch to zoom and use two fingers to move the original photo. Use one finger to adjust the selected box or draw a new one in addition mode. Open the full-screen crop editor for more room, or enlarge the processed preview to check details. Rotating turns the original and its crop boxes together; zooming alone does not change the saved crop.
Why do new questions appear in black and white?
New questions default to Pure B&W for printing. Choose Original or Optimized if that keeps a diagram or faint text clearer. Existing saved questions are not changed automatically.
Can I edit a question after saving it?
Open its folder, open the question, then choose Edit Image. Adjust the crop, rotation, print effect, or erasures, then save to update the same question. Cancel leaves the saved image unchanged. New captures retain the first cropped image before effects and erasures; you can revise edits within that crop, but cannot return to the full page. Older questions use their existing image as the starting point, so previously removed content or colors cannot be restored. Already generated PDFs stay unchanged; create a new worksheet to include the edited image.
What if saving several questions stops partway through?
Successfully saved questions are kept. Choose Save Remaining to retry only the unsaved questions without duplicating successful saves. Leaving the screen keeps saved questions but discards unsaved drafts; those drafts cannot be resumed after closing the session.
How do I build my Mistake Book?
Save questions you want to practice again and organize them in folders. Update each question’s review status after practicing. Your Mistake Book holds the saved questions; Worksheets holds your generated PDFs.
How do I create a Worksheet?
Open Create, select saved questions, then open Layout preview to adjust question sizes if needed. Apply the settings and choose Create Worksheet to generate the PDF. Follow the worksheet tutorial.
Can I adjust question sizes?
Yes. In the iOS layout preview, choose automatic, half, or full width and adjust image size from 60% to 100%. Questions are arranged and paginated automatically. There is no arbitrary position dragging, resize handle, individual question deletion, or layout Undo/Redo. Return to question selection to change which questions are included before creating the PDF.
How do I export or print a Worksheet?
Review the generated PDF, then open it from Worksheets. Use Share to send it or save it to Files, or Print to open system printing. AirPrint requires a compatible printer and a working connection.
Where is my data stored?
Question images and PDFs are stored locally on your device. There is no app account or cross-device cloud sync. Export PDFs you want to keep before uninstalling. Optional analytics and purchase processing are explained in the privacy policy.
Can it automatically remove handwritten answers?
The app provides a manual white brush, not automatic handwriting recognition or answer removal. Use brush undo or restore while editing and check that the question and diagrams remain intact. In iOS 1.2, saved images can also be reopened with Edit Image, subject to the original-crop and older-image limits described above.
Why is capture, import, or printing unavailable?
Import uses the system photo picker. Camera access is needed when you choose to take a photo. Check system permissions, or import an existing image when the camera is unavailable. Printing is handled by the system print service; check the printer connection and paper settings, or save the PDF and print it later.
How does MistakeKit Pro work?
A seven-day local trial lets you try PDF creation. Trial expiry does not delete your material. You can still add, organize, and edit questions, and open, share, or print existing PDFs. Creating new worksheet PDFs requires a one-time MistakeKit Pro purchase. There is no monthly subscription; the app shows the current localized StoreKit price. There is no cross-device app sync; export material you need before uninstalling.
How do I restore a purchase?
On iOS, use the App Store account used for the original purchase. On Android, use the original Google Play account. Choose Restore Purchases in the app’s settings or upgrade screen. Check your account and connection before attempting another purchase.
Why has an old PDF not changed?
A generated PDF preserves its original content. Editing a question image or changing its review status does not regenerate an existing file, and the app does not edit generated PDF content. Create a new worksheet for updated content. Deleting an original question does not automatically remove its image from historical PDFs.
Contact support
Email penyuong@gmail.com with your platform, app version, steps, and the error you see. Attach only necessary material you are authorized to share, after removing student names or other private details. You choose when to send the email.