Case study — AI product design

Spellnotes

Reimagine task management, but with fun fictional characters: what if AI characters were the ones reminding you to go to the gym, buy that milk, or call your mom?

ROLE
Solo product designer, UX researcher, and AI developer
TIMELINE
June – July 2025
TOOLS
Figma, Bolt
CONTEXT
Built for a hackathon
Spellnotes home screen Muffin-generated notification example User adding a new notification

What if your task manager spoke to who you are, not just what you do? Spellnotes has your task reminders delivered by an AI character of your choice, making mundane task reminders entertaining instead of tedious and generic.

Note: while this is a generative AI app, it is not conversational — users can't respond to notifications with text, and all characters are 100% original.

01 — The problem and the pitch

Current reminder apps are boring and/or hard to use

Task management apps are typically boring and have cluttered UI. Notifications are easy to ignore, leading to missed tasks and procrastination.

SOLUTION

Spellnotes introduces a large library of AI assistants with distinct personalities that adapt to user lifestyles and goals. Instead of generic reminders, users receive contextually relevant reminders — creating a personalized, entertaining productivity experience with a relatively simple, intuitive layout that makes it easy to jot down reminders on the go.

02 — Real-world stakes

Not wanting to deal with potential disastrous consequences

I already knew anthromorphized consumer AI had several risks, so, my research and design process was rather non-linear — I started by learning about the negative impact of consumer-facing chatbots like ChatGPT and Character.ai, the product most similar to mine.

Some of the devastating consequences of generative AI misuse include:

😞 In October 2024, Megan Garcia filed a federal lawsuit claiming Character.ai was responsible for the death of her 14-year-old son, Sewell Setzer III, who died by suicide after spending months interacting with a chatbot on the platform — among the character's last messages were suggestions that he take his own life.
😞 Mental health professionals have increasingly reported "AI psychosis" — psychological distress from unhealthy relationships with AI systems, including over-attachment, confusion about AI capabilities, or difficulty distinguishing AI responses from human interaction.
😞 Character.ai has faced multiple lawsuits over user-created bots of copyrighted characters, leading to large-scale deletions of user-created characters and disappointment from users who received no prior notice of the deletion drive.
03 — Learning ethical consumer AI design

Proceeding with caution

After becoming aware of the risks of consumer AI such as hallucinations, AI psychosis, and more, I knew it was critical to study how to design AI interfaces to account for those risks. I understood that design alone couldn't 100% prevent misuse, but certain designs would help mitigate unwanted system output and user behavior.

Everyday risks of LLMs, from Scale AI

I worked through a reading list on AI interface design — including UX for AI and an AI Product Design certification — alongside several articles on human-centered, accessible, and transparent AI interfaces.

UX for AI book AI Product Design certification
04 — Studying the existing examples

Key lessons in AI interface design

What mental models have users already developed from task management and AI companion apps?

Since I couldn't find any task management app with AI companions, I knew Spellnotes was going to introduce an unfamiliar experience — a real usability risk. To design something intuitive despite that, I studied current task management and AI companion apps, taking note of shared patterns in information hierarchy and new-task creation flows, like Todoist's notification structure and how a plain-text app compares to Spellnotes' character-voiced approach.

Todoist notifications, for comparison Plain text app compared to Spellnotes

Below is how other AI companion apps structure their character profile pages, often including usage frequency and other metrics as social proof:

Nomi AI character profile
Kindroid character profile
Nomi AI character detail
Kindroid character bio
My Kindroids list view

Pain points users already have with AI characters

To learn about everyday problems with AI-generated characters, I dove into the Character.ai subreddit. These were the main pain points I found:

Character.ai pain point: age restriction

Age restriction: Users were concerned with minors accessing chats with mature themes, and with models being trained on inappropriate input from minors.

HOW I'LL ADDRESS THIS

Spellnotes will always be 100% SFW, with only diverse pre-made characters rather than user-created ones. No character will have sexually suggestive imagery, violent backstories, or mature themes inappropriate for minors, and users can easily report a character that breaks this.

To figure out how to write the system prompts behind each character, I took courses on prompt engineering, then tested whether current LLMs could deliver entertaining notifications in-character. I started with archetypes I assumed might be popular by local techie users.

Silicon Valley Techie notification example
Spaceship AI notification example
Board Game Cafe Regular notification example

Note: I only tested model responses with mundane, simple, common reminders — I assumed many users would enter more complex or possibly inappropriate reminders in an attempt to troll or evoke an emotionally intimate (or worse) response, and I didn't feel equipped to handle that kind of undesirable behavior on my own.

That's why, if I could hire a team to fully develop this product, I'd choose AI-savvy engineers committed to programming strong guardrails into each character to handle inappropriate requests and detect emotionally risky behavior, such as suicidal ideation. The team and I would test each character against a wide range of potential input, informed by more in-depth primary user research.

05 — Designing for inclusivity

Who would these characters be? How would they look?

I was committed to making the characters diverse in every way, without reflecting societal stereotypes. For the sake of the hackathon's time limit, I used OpenAI's Sora to generate placeholder images and used non-human characters for demo purposes.

With unlimited time and budget, I'd instead design and develop a character customizer like the ones used in video games for human or humanoid characters — letting each user customize features like skin and hair color to reflect their own identity.

Character customization concept
06 — Design principles

AI interface design principles I designed around

ChatGPT disclaimer example

Transparency: The system should inform users of its limitations, such as stating it can make mistakes or that its training data may be outdated.

"Trusted AI is built on transparency, accountability, and a commitment to accuracy."

— Salesforce's Trusted AI Principles

Salesforce Trusted AI Principles
07 — From mockup to code

Designing for an unfamiliar product

Designing something genuinely unprecedented was going to pose a challenge for intuitiveness and trust. I assumed new users wouldn't intuitively figure out how to use the app efficiently, and that some users might be at risk of becoming excessively emotionally dependent on it.

SOLUTION

An onboarding process that clearly walks users through the app's most distinctive features and branding, while introducing the characters' limits through Community Guidelines: they're casual assistants created for entertainment, not emotionally intimate companions or therapists. I kicked off onboarding with reminders that Spellnotes is built for everyday scenarios — like "a list of clapbacks for the next family reunion," not just "go to the gym" — reinforcing its value beyond the AI characters themselves.

Phone verification onboarding screen First notification setup onboarding screen
08 — Personalization

Customizing character dialogue

One unique feature of Spellnotes is that users are encouraged to fill out a profile so their chosen AI assistant can personalize reminder messages — including entering their goals, as is common on other task apps. The difference here is that goal input further personalizes the generated AI reminders themselves.

Task reminders in the voice of an AI character are pretty much unheard of, so I assumed some users would be skeptical of how useful or entertaining the app would be for their specific use case.

SOLUTION

During onboarding, users can optionally set up a single notification and select one character to deliver it, with a preview of what it'll look like — quickly familiarizing them with an unfamiliar mental model and their future user journey.

User adding a new notification User adding a new notification Muffin-generated notification example Muffin-generated notification example

After selecting their first assistant and setting up their first notification, users land on their home screen — designed like a simpler version of the other task apps I studied, with one core objective: let users jot down a note and reminder time as quickly as possible.

Spellnotes home screen Spellnotes home screen

Not all notifications need to be spoken through a character's voice — they don't need to know everything about us. That's why every reminder has the option to be delivered exactly as the user entered it, with no AI modification.

Designing for emotional safety

As discussed earlier, frequent interaction with AI that mimics humans is strongly associated with emotional risk, like excessive attachment.

SOLUTION

At least one page is dedicated to these issues, so users are aware of the risks and can quickly access mental health resources — just in case some are already experiencing symptoms while using the app. There's also in-app feedback submission.

Mental health resources screen

AI characters are also prone to unwanted, unsettling output. I designed feedback loop mechanisms into the notifications themselves, but assume those may not always be enough for more severely unhinged AI behavior.

SOLUTION

Users can report a character directly from its profile page, and submit any other concerns right in the app rather than having to send an email.

Reporting an issue with a character

Spellnotes also lets you save any task in plain text, so you can read it as written without an AI character involved — just like on any other task management app.

Reflection: I later changed Muffin the Fluffy Bunny's character trait from "caring" to "practical," realizing that describing an AI as "caring" might inadvertently evoke emotional attachment.

09 — Reflection

Responsible AI needs more than good interface design

This project reinforced that ethical AI development isn't just about interface design — it's about organizational commitment and ongoing accountability. While I'm proud of the personality system and safeguards I designed, I'm acutely aware that launching this responsibly would require resources beyond a solo designer-developer.

The team this app actually needs

The risks we've seen with Character.ai and OpenAI's legal challenges are lessons in the consequences of inadequate safety considerations. AI personality design needs expertise in parasocial relationships, attachment theory, and digital wellbeing — not just engagement metrics. I'd want every team member on this app to be well-versed in ethical, responsible AI design and genuinely committed to user wellbeing.

The hardest design challenge for Spellnotes isn't making the AI feel personal — it's knowing when to make it feel less personal. Balancing fun, mentally stimulating characters against emotional distance to mitigate harm was difficult. If this app were to scale, I'd intentionally implement friction points: reminders that the assistant is AI, cooldown periods between interactions, and deliberately non-human response patterns — though these would need validation from mental health professionals and iteration based on real usage.

The most important design decisions in AI aren't just the ones users see — they're the constraints, safeguards, and organizational commitments that protect users from risks they might not even recognize.

View the non-AI version of this app

I later made another non-AI to-do list app inspired by this one.

See app