Feature Suggestion for GoodNotes: Color-Based Review/Masking Mode
Subject: Innovative Study Feature: Color-Based Toggle for Hiding/Showing Annotations (Killer Feature for Students)
1. Background and User Need
I am a long-time user of iPhones and MacBooks, yet I prioritize using the Samsung Galaxy Tab because of its superior writing feel and the ability to instantly annotate PDFs. I am currently preparing for professional exams, which requires intensive review and memorization.

To optimize my study routine, I use a physical method similar to a 'secret pen', where I hide the answers and solutions for efficient self-testing. Implementing this concept into GoodNotes would create a massive competitive advantage and drastically improve the learning efficiency for all students and test-takers.

1. Proposed Feature: Color-Based Toggle for Hiding/Showing Ink I propose adding a 'Color-Based Masking/Review Toggle' feature to GoodNotes.

How it Works:

Setting: Introduce a dedicated setting (e.g., within the Pen Tool Palette or a separate menu) called 'Color Masking Mode'.

Toggle Action: The user selects specific pen colors (e.g., Red, Pink, Highlight Yellow) and designates them as 'Hidden' colors.

When the global 'Review Toggle' switch is activated (e.g., a simple button on the toolbar):

All annotations written in the designated 'Hidden' colors instantly disappear from the screen.

Toggling the switch again makes the hidden ink reappear immediately.

1. Key Use Case (From a Test-Taker's Perspective) Preparation: Open a practice test PDF. Write the correct answers in Red and brief explanations in Pink.

Repeated Study: Activate the 'Review Toggle' to instantly make the Red and Pink ink disappear. This provides a clean, blank test paper for quick re-testing without the need to duplicate or erase the PDF.

Instant Check: After self-testing, toggle the switch off to re-display the Red answers and Pink explanations in 1 second, allowing for lightning-fast answer verification.

1. Expected Benefits Maximized Learning Efficiency: Eliminates the need to duplicate $\text{PDF}$s or tediously erase and rewrite answers, saving significant study time.

Competitive Edge: This is a unique feature currently absent from major competitor note-taking apps. It would serve as a powerful 'Killer Feature' to attract the large and lucrative market of students and professional exam candidates to GoodNotes.

High User Satisfaction: This function addresses a core pain point for GoodNotes' primary user base, ensuring high practical utility and satisfaction.

This function has the potential to revolutionize digital note-taking for academic and professional preparation. Thank you for your time and consideration.