Quillin'

An iPad app for handwritten notes

Abstract

We developed a handwriting notes app inspired by the challenges of keeping up with handwritten notes in class and the desire for better organization. Combining features from apps like Notability and GoodNotes with handwriting recognition and LLM-powered chat, the app allows users to take notes and interact with an AI assistant for clarification or expansion.

Starting from a Figma design, we built a native iOS app in Swift with a FastAPI backend. Third-party services—including Groq, Google Cloud, and Railway—supported handwriting recognition and cloud functionality.

Problem

The first time I heard about linear dependence in math class, I was completely lost. The concept didn’t click at all, and I didn’t know how to ask a question—especially in a lecture hall of 300 people, where raising your hand feels intimidating. The slide-up desks were tiny, leaving barely enough space to write, let alone manage my notes and laptop. Most of my classmates in the math program use iPads to take neat, organized notes, while I was juggling pen and paper.


Trying to keep up, I put my pen on my lap and opened Chrome to ask ChatGPT what linear dependence meant. As I shifted to type, my pen slipped and fell to the floor. I bent down to pick it up, and by the time I looked back, I had missed a minute of the lecture—enough to miss the professor’s explanation of trivial solutions.


Later, back in my dorm room doing homework, I stared at my notes and realized they contained symbols and letters I didn’t even know how to type on my laptop. Unsure how to even frame a question, I ended up sending a screenshot to a friend majoring in applied math. They explained what my notes actually meant, revealing the concept I had struggled to grasp on my own.


Here are some of the problems we identified with this setup.

  1. Switching between typing and using the Apple Pencil is cumbersome

  1. Handwritten notes, especially those with symbols or notations, are difficult to transcribe or convert into text.

  1. Hard to ask quick questions or learn interactively in the moment

Solutions

  1. Transcription to LaTeX

For notes where you’re unsure what you wrote, quickly convert handwriting into readable math notation.

  1. One-Step LLM Asking

Send handwritten notes to the AI all at once for faster understanding

  1. Three Suggested Questions

The app proposes relevant questions automatically to guide your learning, without the need of switching tools.