Why there is no in-app purchase in Heddy
Open Heddy on a child's phone and look for the shop. There isn't one. No upgrade button, no credit pack, no subscription sheet, no price on any screen a child can reach. A grown-up buys a plan on the web, and the app unlocks itself. This is the decision I get asked about most, and it is the one that costs us the most.
Heddy went live on the App Store on 22 September 2026. It is a free download, it teaches the UK Key Stage 3 curriculum across seven subjects to 11–14 year olds, and it has eight tutors in it: Heddy herself, a snowy owl who meets you at the door, and seven subject professors — Pi for maths, Newton for physics, Curie for chemistry, Darwin for biology, Quill for English, Harari for history, Mercator for geography.
What it does not have, anywhere in the build, is a way for a child to spend money.
What it costs us to do it this way
Let me start with the part that is bad for the business, because it is the part that makes the rest of it believable.
There is a moment in Heddy where a student has used up their free tutoring turns. They came to the app with a real problem — a Year 8 equation at half nine on a Tuesday, with the homework due tomorrow — and they were mid-way through understanding it when the free allowance ran out. They are focused. They are motivated. They want more of exactly the thing we sell.
In commercial terms, that is the best moment in the entire product. Every instinct in software design says put the offer there. Put it right there, on that screen, while they care.
Here is what is actually on that screen: Heddy dozes off, eyes shut, and the student gets two buttons. Practise cards. Remind me tomorrow. No price. No "ask a parent to upgrade". No little lock icon with a shimmer on it. The highest-intent moment in the product carries no offer at all, and the student's next tap takes them to flashcards, which are free forever.
I am not going to pretend that is free for us. It is a harder, slower, lossier path to a paying customer than the obvious one, and there is no version of the maths where it isn't. We pay that cost deliberately. Here is why.
A price a child can see is a price a child can be persuaded by
The industry has a polite name for the alternative: pester power. It means designing the purchase moment so the child does the selling for you.
You never have to be crude about it. You don't need a cartoon character to beg. You just have to put the price where a frustrated thirteen-year-old will see it, at the moment they are most frustrated, and let the rest happen at the kitchen table. The child asks. The parent, who was not there when the moment was engineered and has only a tired teenager in front of them, says yes or no. Either way, the decision was shaped by a screen the parent never saw.
I do not want to build the screen that starts that conversation. Not because a rule says I can't — this is our own call, made for the family's sake — but because of what it does to the relationship between a student and a tutor. The whole premise of Heddy is that the professor on the other end has one interest, which is whether you understand the thing. The instant that same professor is also the one who shows you a price when you are stuck, that claim is no longer true, and a teenager will work out that it is no longer true faster than any adult expects.
The four-rung hint ladder exists for the same reason. A tutor who will not hand over the answer is only credible if he has nothing else he wants from you.
A free tier has to be usable, not a trial
The other half of this is what makes it survivable, and it is the reason I can write the paragraph above without it being a stunt.
Flashcards in Heddy are free forever. Unlimited, no card details, no sign-up to look around. Six ways to be asked — flip, type, choose, say it out loud, order the steps, fill the gap — and the cards come from the student's own sessions, so the thing they got wrong last night turns up as a card in the morning. There is no daily cap and there never will be.
That is not a generous-sounding footnote. It is what makes the no-purchase screen honest. If the free tier were a countdown — a taste of the product, then a wall — then removing the price from the wall would just be cruelty with better manners. The student would be stuck, and we would have arranged for them to be stuck, and the two buttons would be a way of making the trap look thoughtful.
Instead, running out of tutoring turns moves a student sideways into a part of the app that is genuinely good and genuinely unlimited. There are twenty tutoring turns to try, with Mentor and one professor, and the counter is deliberately a counter and not a meter: the student always knows how much is left, and nothing ever runs out mid-sentence. A hint ladder that has started always finishes. The full detail of what is metered and what isn't is worth reading if you want the economics rather than the principle.
The parent holds the money, and the decision
So where does the money actually happen? On the web, at aitutors.me, in a grown-up's own account, on a grown-up's own screen.
Heddy Plus is a monthly, per-child plan. It opens all seven professors instead of one, removes the turn counter entirely, and adds the homework photo, so a student can snap a question and work through it line by line. You buy it as yourself, in a quiet moment, with the actual information in front of you — not because someone appeared at your elbow at ten at night.
And when you do, the app unlocks itself. Your child does not enter a code, does not restore a purchase, does not see a receipt. The next time they open Heddy, the other professors are simply there.
The homepage puts it in eleven words: No in-app purchase to tap by accident. A grown-up buys plans on the web. And, from the parents' section: You hold the money — plans are bought here on the web. The child never sees a price.
That second sentence is the one I would defend hardest. Not "the child can't buy things" — plenty of apps achieve that with a password prompt, which still shows the child the price and still starts the conversation. The child never sees a price. There is nothing to want, nothing to ask for, and nothing to be disappointed by.
What you get instead is a weekly note rather than a dashboard: what your child worked on, what clicked, where they are still stuck. The professors stay on their own subject and refuse the rest, and anything serious is flagged for review and ends the session so a parent can be told. The fuller safety picture is here.
None of that works if the app is also, quietly, a shop. So it isn't one.
Published 23 Sep 2026. Written by Duke Harewood, who builds the tutors at aitutors.me. Heddy is free on the App Store.