I stopped trying to limit screen time and gave it a price.

THE PROBLEM

Every evening, the same argument

In most homes with children, screen time is not a policy. It's a running negotiation that resets daily, and both sides are exhausted by it. Parents end up cast as enforcers of a rule they have to re-argue from scratch every time, and children experience the whole thing as something being taken away from them for reasons they had no part in.

I'd watched this up close, and what struck me was that nobody involved was enjoying the dynamic, including the parents doing the enforcing. I wanted to design something that didn't just regulate hours, but changed who was making the decision.

DESK RESEARCH

What the published data said

I started where the evidence already was. Research on prolonged screen exposure in children reports that a majority become more lethargic and sedentary, over half prefer to stay alone, a similar proportion show more aggressive behaviour, and a substantial share see their academic performance suffer.

What the literature couldn't tell me was why the existing solutions weren't working. Every parent in this situation already knows screens are a problem. Knowing that hasn't helped them.

PRIMARY RESEARCH

Twelve parents, and the thing they all said differently

So I recruited twelve parents of children aged five to twelve for one-to-one interviews, and asked them to walk me through how they actually manage screen time, not what they intend to do, what happens.

What came back wasn't a set of feature requests. It was a set of feelings.

I synthesised these through affinity mapping and a problem tree analysis, which surfaced ten root causes - balancing time, developmental concerns, work-life demands, guilt about content, the screen-centric culture the children live inside. But almost every branch traced back to the same trunk: the negotiation never ends, and the parent is always the one holding the line.

THE REFRAME

The paradox that changed the project

Then one finding rearranged everything. Around 40% of the parents I spoke to felt their children were using screens passively, consuming, not engaging, not making anything, not choosing anything.

That reframed the problem for me. The issue was never purely the quantity of screen time. It was that screen time had no cost attached to it and no decision inside it. A child given two hours and a child given four hours are doing the same thing: receiving an allocation somebody else set, passively, with no stake in it.

Which turned the design question into something much more interesting than how do we limit this. It became: what if screen time were something you had to choose to spend?

THE IDEA

Children already understand trade

A thread running through the interviews was that children respond well to systems of trade and reward. They already understand earning something and spending it; that logic is intuitive long before anyone explains economics to them.

So there were two paths in front of me. Path A, build a better version of the traditional screen-time limiter, which is what every existing product does. Path B, build a currency. Children earn coins for chores and responsible behaviour, and spend them on screen time at a fixed, visible rate: one coin, sixty minutes.

Path B moves the decision from the parent to the child without removing the parent's control, because the parent still sets how many coins exist. The child isn't being told no. The child is being asked whether this is what they want to spend on.

VALIDATION

I tested it in five homes before I designed a screen

A coin-based model is either obvious in practice or it collapses the first time a real seven-year-old encounters it, and no amount of wireframing tells you which. So before I opened Figma, I ran the concept manually in five families for a week, physical coins, parents setting the allocation, children spending them, no software at all.

Two techniques did the work. A Wizard-of-Oz setup, where the parent performed the role the app would later play, issuing coins, approving the exchange. So I could watch the interaction before building the machinery behind it. And a Pinocchio prototype: a non-functional stand-in for the coin, so children were handling something real without me having built anything.

What came back after seven days:

Small numbers, and I'll say so plainly, five households is a signal, not a proof. But it was enough to tell me the core exchange was legible to children without an adult translating it, which was the one thing that had to be true before any of the rest was worth designing. And the parents' own reports of increased accountability were consistent enough to be worth taking seriously.

LANDSCAPE

Nobody was doing this

A competitive analysis across Qustodio, OurPact, Forest and Calm confirmed what the interviews had implied. There are good products for restricting screen time, blocking apps, and building focus habits for adults. There was no product where a child spent something to get screen time. The whole category was built around restriction, and restriction is precisely the thing the parents I spoke to were tired of administering.

DESIGN

Three bridges

I reduced everything the research had produced into three problems the product had to solve. They became the spine, every screen had to serve one of them, and anything that didn't got cut.

I started with a storyboard rather than screens, a scene of a parent using CoinQuest at home, and then low-fidelity wireframes, with the flow deliberately split into two paths from the beginning. A parent's journey and a child's journey, meeting at exactly two points: the allocation, and the prompt.

A picnic, not a dashboard

Parental-control software mostly looks like surveillance software, which is a fair description of what it does and a terrible fit for a product meant to bring a family closer together.

So the visual direction went the other way: a nature and picnic palette, warm rather than clinical, something a family could recognise itself in. The golden hue is reserved for the coins, because the coin is the thing that carries value and it should read as valuable. The logo is built around the idea of a quest, a journey toward responsible use, rather than a lock on a door.

The parent's side: set the budget once

The parent flow is built around removing a recurring decision rather than adding a new dashboard to check. Parents avail virtual coins, create a profile for each family member, and allocate the week's coins at the start of it. That's the work. Everything after is optional: analytics on how time was actually spent, which apps consumed it, and the weekly leaderboard.

The thing I'd defend here is the weekly cadence. A daily allocation just recreates the daily negotiation in software. Setting the week's budget once is what converts an argument into an agreement.

The child's side: the first real choice

When a child opens a managed app, they meet a prompt: here's your balance, here's what this will cost, do you want to spend it? They can spend, or go back. A coin animation makes the transaction feel like something happened, because to a child it should, a balance silently decrementing teaches nothing.

That prompt is the emotional centre of the product. It is the first moment in this entire dynamic where the child is the one deciding, and it reframes the whole relationship without removing any parental control: the parent still determines how many coins exist.

Spending on educational content earns points toward the leaderboard, which is where the system quietly makes its argument, not all screen time is the same, and the child gets to discover that through their own spending rather than being told.

The shared part: something to be proud of

The third bridge was the one I could most easily have skipped, and it's the one that makes the product more than a wallet. Parents can see how coins were spent, which apps dominated, and where their child landed on the leaderboard, and they can share that result.

Sharing sounds like a social feature bolted on. It isn't. It's the only mechanism in the product that lets a parent respond to screen time with pride instead of policing, which is exactly what the interviews said was missing.

TESTING

What the numbers say, and what they don't

I tested the prototype with five participants across thirty tasks and more than 200 minutes of sessions, asking each person to rate ease and confidence per task from zero to five, and scoring completion myself.

The more useful result sits in the week-long home test earlier: children understood the exchange without an adult explaining it, and parents reported less screen time. That's behaviour in a real environment, which is worth more than a task-completion rate in a session.

REFLECTION

What CoinQuest taught me

The thing I keep coming back to is that control and autonomy are not opposites. I started this assuming the design problem was finding a fair point on a slider between parental control and child freedom. It isn't a slider. The parent kept full control over how many coins exist, and the child gained complete autonomy over how to spend them, and both sides ended up with more than they had under a straightforward time limit.

The second thing is about where the design work actually happened. The product's best idea isn't an interface decision at all; it's an exchange rate. One coin, sixty minutes, and once that was right, the screens were comparatively easy. If I'd started in Figma I would have designed a very polished version of the wrong product.

And the third: the week in five kitchens told me more than any amount of wireframe review would have. Testing a concept before an interface exists is cheap, slightly awkward to arrange, and the highest-value hour in the whole project.

CoinQuest · graduate thesis, 2024. With thanks to the twelve parents who talked to me candidly about something difficult, and the five families who ran a stranger's idea in their homes for a week.