PDF Study App: Red Sheet

PDF Study, PDF Memorization, and PDF Masking in one simple study app.
Turn your own PDFs, notes, textbooks, handouts, worksheets, screenshots, and images into powerful study materials.

This app helps you hide and reveal text, answers, formulas, diagrams, definitions, and important parts of your materials.
Instead of only reading PDFs, you can mask the parts you want to remember, try to recall the answer, and tap to reveal it while studying.

It is designed for students who want a PDF study app, PDF memorization app, PDF mask tool, flashcards maker, and active recall study app in one place.

PDF Study & PDF Memorization
- Import PDF files and study directly from the page
- Turn PDFs into interactive study cards
- Hide answers, terms, formulas, diagrams, and explanations
- Mask important parts of your PDF for self-testing
- Tap hidden areas to reveal answers while reviewing
- Study lecture slides, textbook pages, worksheets, and handouts
- Create your own PDF memorization materials without printing
- Review PDF pages smoothly with vertical scrolling

PDF Mask & Hide Text
Place adjustable blocks anywhere on a PDF page, note, or image.
You can hide text, numbers, definitions, formulas, solutions, labels, translations, and key points.
Use PDF masking to cover only the parts you want to memorize, then reveal them when you are ready.

This is useful for:
- Hiding answers in PDF worksheets
- Masking definitions in textbook pages
- Covering formulas in math or science notes
- Hiding vocabulary meanings in language notes
- Covering labels in diagrams, maps, and charts
- Turning lecture slides into review materials

Flashcards Maker from PDFs
Create flashcard-style study blocks directly on your PDFs and images.
You do not need to type every question and answer manually.
Import your existing study materials, hide the important parts, and start memorizing right away.

This app is useful when you already have:
- School PDFs
- Class handouts
- Textbook pages
- Lecture slides
- GoodNotes or notebook app exports
- Screenshots from online classes
- Photos of notebooks or whiteboards
- Worksheets and practice questions

Study Notes & Image Memorization
You can also create flashcards from photos, screenshots, handwritten notes, printed materials, and whiteboard images.
Hide words, formulas, answers, or diagrams like covering part of a card.
Tap to reveal the hidden area while reviewing.

This makes it easy to turn paper materials into digital study cards and review them anytime on your phone or tablet.

Active Recall for Faster Memorization
This app is built for active recall.
First, hide the answer.
Next, try to remember it.
Then, tap to reveal and check yourself.
Repeat until you remember it.

Active recall is helpful for:
- Vocabulary memorization
- Exam preparation
- Science terms
- History facts
- Geography labels
- Language learning
- Certification exams
- University study
- Middle school and high school study

Why This PDF Study App Is Useful
Many PDF reader apps are made for reading.
Many flashcard apps require you to create cards from zero.
This app lets you study from the materials you already have.

Import.
Mask.
Recall.
Reveal.
Repeat.

By turning PDFs, notes, and images into hidden-answer study materials, you can make your review more active, focused, and efficient.

Recommended for people who want:
- A PDF study app
- A PDF memorization app
- A PDF mask tool
- A flashcards maker from PDFs
- A way to hide text in PDFs
- A study app for notes and images
- A memorization app for exams

How to use
1. Import a PDF or add photos
2. Hide text, answers, formulas, or diagrams
3. Tap to reveal hidden parts while studying
4. Repeat and memorize at your own pace

Whether you are preparing for school tests, university exams, language study, certification exams, or daily review, this app helps you study PDFs, notes, and images more actively.

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Recent changes:
The PDF study features have evolved!
You can now memorize content in handwritten PDF notes too!
I hope this PDF study app helps you with your learning!