Game Tailors
Source: Designed with respect for children
The drawing app where the paper is real. No ads. No accounts. No personal data: only anonymous counts, which you can switch off.
Game Tailors · Schieweg 15Y-40, 2627 AN Delft (NL)
KvK 92437702 · VAT NL866044474B01
info@gametailors.com · +31 6 4227 5919
© 2026 Game Tailors
Designed with respect for children
Before the shop was built, we read what regulators, app stores and child researchers say about games and money. Almost all of it points one way. So Professor Oops has no ads, nothing locked or priced in play, one purchase for grown-ups behind a sum, at most three polite asks, and very little data sent. Where we chose to be softer than the strictest reading, this page says so.
A child who opens Professor Oops finds tabs full of tools that work. The free version has whole tabs (the kitchen, the science kit, the toolbox), the drawing tools, and a few more things such as water and the sponge. A tab that would otherwise have nothing free gets one "taster" that says what the tab is about: the face plant in the toy box, the ants in the garden. Nothing is greyed out. Nothing has a padlock. No character says "ask your parents".
That isn't an accident of style. European law lists, among practices that are always unfair, a direct appeal to children in an advert to buy something or to get an adult to buy it for them EU 2005. The UK's games principles give examples of what is unlikely to comply, such as an unhappy cartoon character used to push a purchase OFT 2014. The US Federal Trade Commission names "parasocial relationship pressure", a loved character used to sell FTC 2022.
Researchers who coded 133 apps played by 160 children aged 3 to 5 found that about four in five used at least one manipulative design: lures, time pressure, a character asking for money. One app said "You can play with these cute animals for a tiny fee! Ask your parents!" Radesky 2022. We built to the other side of that line.
In play we do show one thing, and we want to be clear about it. At the end of a tab with more in the full version, there is a small paper tile with reading glasses and a number, like "+12". It has no tool pictures, no words, no price and no padlock. It never moves, glows or makes a sound. Tapping it opens the grown-ups' sum. The strictest reading of the research said to show no sign of the paid tools at all. We decided a quiet door for grown-ups is fair, and we put it on the ladder below where it belongs.
Our first ideas for selling the full version were warm ones. They were also, it turned out, the very patterns the research warns about. Here is what each one became.
First idea · Dropped
Pester power by design: point 28, "persuade adults to buy it for them" CPC 2025, and the "just ask your parents" pattern Radesky 2022. A gate in front doesn't cure it.
Built instead: A welcome gift for every family, the ants, with no condition and no announcement. It arrives on the second launch.
First idea · Dropped
A one-chance offer is scarcity aimed at a purchase, the kind of pressure the Dutch regulator fined ACM 2024. And the child would see the loss.
Built instead: Nothing given is ever taken away. No trial expires.
First idea · Dropped
"Come back tomorrow" was coded as manipulative Radesky 2022; it is a streak in all but name.
Built instead: "One tool a day" exists only after buying, as a grown-up's choice. A missed day just means the next tool comes later.
First idea · Dropped
Many small products multiply the moments to buy, and children want specific animals, so each one invites its own pestering.
Built instead: One product: the full toolbox.
First idea · Kept, with limits
A request with no permanent "no" is nagging FTC 2022.
Built instead: Three asks in all, a week apart, each with "No thanks, don't ask again".
Anything a grown-up must decide sits behind a short addition: the grown-ups' area, the offer and its price, paying, and a link out of the app. Apple asks kids' apps for "adult-level tasks" in front of such things Apple Kids. The sum is a two-digit number plus a round ten, never more than 100, like 37 + 40. A wrong answer brings a new sum, so the answer can't be found by trying. Three wrong answers close it, and the child is back at play with nothing lost.
Our research asked for something harder, a task a ten-year-old couldn't solve casually. We started with a multiplication, then an addition with a carry, and found both too hard for a quick grown-up step. So we made it easier, twice, on purpose. It is a real hurdle for a five-year-old. We expect it won't stop many eight- to ten-year-olds, and we don't pretend it does. We also looked for a controlled study showing that parental gates work at all, and found none. So we rely on what's behind it: no urgency, no countdown, and the store's own payment sheet after the offer.
In the next update a grown-up can switch the sum off for the area, the tour, saving a picture in the apps and redeeming a code next update. Paying and a way out of the app still ask unless a grown-up has just solved the sum, and more play time always asks, so a child can never give themselves more time.
The sum is drawn by the game's own rule, and checked with three tries as in the game: a wrong answer brings a new sum. It types answers by itself until you tap the keys, or use the buttons. What to look for: how fast a grown-up gets through, and that a wrong answer costs a try but never a scolding. Three wrong and the door closes, back to play.
This part of the page could not start.
The 252 sums give answers from 31 to 99; the likeliest, 91, comes up 4.1 % of the time.
| the answer (a + b) | chance of each answer |
|---|---|
| 31 | 0.23% |
| 32 | 0.23% |
| 33 | 0.23% |
| 34 | 0.23% |
| 35 | 0.23% |
| 36 | 0.23% |
| 37 | 0.23% |
| 38 | 0.23% |
| 39 | 0.23% |
| 41 | 0.49% |
| 42 | 0.49% |
| 43 | 0.49% |
| 44 | 0.49% |
| 45 | 0.49% |
| 46 | 0.49% |
| 47 | 0.49% |
| 48 | 0.49% |
| 49 | 0.49% |
| 51 | 0.81% |
| 52 | 0.81% |
| 53 | 0.81% |
| 54 | 0.81% |
| 55 | 0.81% |
| 56 | 0.81% |
| 57 | 0.81% |
| 58 | 0.81% |
| 59 | 0.81% |
| 61 | 1.21% |
| 62 | 1.21% |
| 63 | 1.21% |
| 64 | 1.21% |
| 65 | 1.21% |
| 66 | 1.21% |
| 67 | 1.21% |
| 68 | 1.21% |
| 69 | 1.21% |
| 71 | 1.73% |
| 72 | 1.73% |
| 73 | 1.73% |
| 74 | 1.73% |
| 75 | 1.73% |
| 76 | 1.73% |
| 77 | 1.73% |
| 78 | 1.73% |
| 79 | 1.73% |
| 81 | 2.53% |
| 82 | 2.53% |
| 83 | 2.53% |
| 84 | 2.53% |
| 85 | 2.53% |
| 86 | 2.53% |
| 87 | 2.53% |
| 88 | 2.53% |
| 89 | 2.53% |
| 91 | 4.12% |
| 92 | 4.12% |
| 93 | 4.12% |
| 94 | 4.12% |
| 95 | 4.12% |
| 96 | 4.12% |
| 97 | 4.12% |
| 98 | 4.12% |
| 99 | 4.12% |
Source: Computed exactly from the game’s own rule: 252 possible pairs, the first number uniform over its 63 values, the round ten uniform over those that keep the total within 100. No answer ever ends in 0.
The game may mention the full version to a grown-up again, but rarely. There are three asks in all. Each one waits at least seven days after the last. Every ask has a plain "No thanks, don't ask again", and after that the game never asks again: the tiles go too, and the start screen simply says "Free version". Only a grown-up can turn the reminders back on, in the settings, and then they come no more often and no more times than before. A family that owns the full version is never asked. A clock set backwards unlocks nothing.
The offer itself has one bold button with the price in it, and "Not now" sits right under it in readable text, never as grey small print. There is no timer, no "only today" and no countdown. The Dutch regulator fined a big game maker €1,125,000 over "buy now" pressure on children and misleading countdowns ACM 2024. The first-launch welcome shows no price at all, as Google Play's Families policy asks Google Families.
Here is a seam we want to show. Our research said "never at launch". From the third launch, though, the start screen's grown-ups' strip can open into a short reminder in words, without a sum first. It shows no price and no tool pictures, and it spends one of the same three asks. It is on a screen a child can see, which is why it holds to the budget.
Each dot is a day the game is opened. Above the line: W the welcome (no price), G the welcome gift, T the strip offering the tour, and flags 1, 2, 3 for each reminder, which is an ask. The shaded weeks are when no ask may come, and pale marks are still to come. Change how often the game is opened, whether a grown-up watched the tour, and what they tap. What to look for: however often a child plays, there are never more than three asks, and "don't ask again" ends them for good. Shaded: the week after an ask. Grey dots: after "don't ask again".
This part of the page could not start.
A grown-up can set a daily play limit of 15, 30 or 45 minutes or an hour. It is off unless they choose it. Two minutes before the end, the painter says so once. At the end the game rests behind "Time for a break!", never in the middle of a stroke, with the drawing saved. Adding 15 minutes for today always needs the sum. There are no streaks and no rewards for coming back. The limit exists because Brazil's new law asks for parental time tools Brazil 2025, and we give it to every family for free.
One study we found later raises a fair question about our two-minute warning. Parents of children aged 1 to 5 reported that their own two-minute warnings made transitions worse, while transitions the technology ended went better Hiniker 2016. Ours comes from the device, which the authors proposed as a possible fix without testing it, and our players are mostly older. We keep it, and we keep watching that question.
Under the hood
The limit is off, 15, 30 or 45 minutes, or an hour; the warning comes two minutes before the end, and "more time" adds 15 minutes. Only time with the game in front counts, and a device that slept doesn't eat the day. The count starts again at local midnight and is kept on the device only. An automated test checks it.
There is one thing to buy: the full toolbox. No subscription, no virtual coins, no gems, no random boxes. Paid random content is a loot box, and Brazil's 2025 law bans those in games children are likely to play Brazil 2025. The toolbox is a fixed, listed set, so there is nothing to gamble on.
A grown-up who buys it chooses how it arrives: everything at once, wrapped as a present to open later, or one new tool a day. Any switch can only bring more, and nothing given is ever taken away. Buying on the web comes with a "Withdraw from purchase" button for 14 days. Where the store country is Ukraine, the full version is free.
"One price" means one product, not one number everywhere. The web price is €5.99, lower in Spain, Italy and Greece (€4.99) and Portugal (€3.99), and the app stores use their own local prices. The flow is always the same: the sum, an offer with the price on it, then the store's own sheet. The US case against a big game maker, settled for $275 million plus $245 million in refunds, shaped that order FTC 2022b.
Professor Oops has no accounts, and the game asks for no name, e-mail address or birthday. (A grown-up who buys in the browser gives the payment page an e-mail address for the receipt.) It carries no advertising code and no analytics library from another company. One study of 5,855 popular free children's Android apps found a majority potentially breaking the US children's privacy rule, mostly through such third-party libraries Reyes 2018. We read that later, and it fits the choice we had already made. On Android, the advertising-ID permission that a library could slip in is removed, and a test holds the list of permissions. On iOS the app declares no tracking. The Android app does carry one partner library, which unlocks the full version on a partner's children's tablets. The released game uses neither the microphone nor the camera.
We do count a little, ourselves. Once a day at most, the game can send a short report of what was used: which tools, how many times, in which language. It has no identifier, no time finer than a day and no free text. The server adds it to daily totals and keeps nothing else from it. Off stores nothing, and switching off deletes the device's record.
Where we read the law as asking for consent first, the counts start switched off: the UK, most of the EU and EEA, and anywhere the country can't be told. We read Dutch, French and Italian rules as exempting this kind of first-party counting, so there they start switched on, like the rest of the world. A grown-up's choice in the settings always wins, and an update never resets it. Like any website, the server sees an internet address with each request, and our hosting provider keeps its own records. That is why we say "anonymous counts" and not "no data".
Stays on the device
Every drawing and saved picture
The play-time limit and today's minutes
The asks record and the gift
The counting's own record: first day, last day, launches (only coarse buckets of it ever leave)
Sent at most once a day, if switched on
Which app (web, Android or iOS), its version and its language
Free or full version
Coarse buckets: how long counting has run, days since last played, launches
Which tools were used and how often, such as the crayon 14 times and ketchup twice
Which colouring pages were opened
No identifier, no time finer than a day, no free text
What the server keeps from it
A count per day for each thing counted, and nothing else
One more report from the web, one more in Dutch, one more second launch
Crayon +14, ketchup +2, the cat-in-the-window page +1
The country +1, on the web only, as a total of its own that is split by nothing
The game lets a child do things they mustn't do at home: pour water on burning oil, mix bleach with vinegar, clip a battery to steel wool. When they do, the painter says what really happens and what to do instead, calmly and once. The burning-oil line comes back at most once a minute. No line scolds.
The fire buttons follow the same idea. During a pan fire the game offers "Put a lid on" and has no water button. Water thrown on burning oil flares up, and flour flares up too. Fire guidance we read later says the same about the lid, turning off the heat and never using water NFPA 2026, Brandweer NL, and health guidance agrees with the bleach line: mixing makes chlorine gas, so get to fresh air Chang 2020.
There is a second fire button, "Damp tea towel", and here the advice is not settled. A UK fire service now warns never to throw water or a damp tea towel over a pan fire Essex 2024, and the American and Dutch guidance we read gives no towel for a pan fire. We'd rather show that here than leave it out.
And creatures are never hurt. A cat, a dog, a pigeon or an ant gets out of the way, and a test puts each of them through dozens of kinds of trouble, from a hammer to an oven. That rule is ours, not a finding from research, and it is what lets us answer "no violence" when the stores ask about the game for its rating.
"Water on burning oil turns to steam at once and throws the burning oil up! If a pan catches fire, call a grown-up: they put a lid on it and turn off the heat. Never use water."
"Bleach and vinegar (or lemon) make chlorine gas: it stings your eyes and lungs! Open the window, or get out into fresh air."
"Only small batteries are for playing with. Never put anything into a plug socket in the wall: that electricity can really hurt you."
"Hot! Wire on a battery can burn. Only try it with a grown-up."
We have no study of our own, and nothing in this page shows that the game changes what children do. The research we found later cuts both ways, and a fair page shows both.
In one study, children aged 5 to 8 who watched a video where people acted dangerously, got hurt and then showed the safe way said they would take fewer risks, and spotted more hazards Potts 1998. Our lines have that shape, consequence then the safe action, though in our game nobody gets hurt. In another, children aged 6 to 9 who watched risky television said they were more willing to take physical risks Potts 1994. Preschoolers carry more of a story's lesson over to the real world when the story's world is like ours Walker 2015, so the game's realism may help a safety line travel, and other things too.
So our rule is that these things stay on screen, and that a grown-up talks them through. That is a rule of ours, not a finding.
Shared: temperature + oil + water
It flares, and the painter says what a grown-up does instead.
Heat and fire · pinned by a test
Shared: acid + bleach → chlorine
A yellow-green cloud of chlorine hangs over the spot, and the line says to open a window.
Chemistry and pH · pinned by a test
Shared: current + heat
The wire glows hot, and the line says only with a grown-up.
Electricity · pinned by a test
Shared: one shared danger channel
The ant scurries out from under it, whatever tool it was.
Animals with their own minds · pinned by a test
Shared: merged manifest
A test fails if an advertising-ID permission sneaks back in.
How we keep it right · pinned by a test
Each entry says how it relates to what we built: applied (we designed to it), informed (it shaped our thinking), found later (read after building; it fits, or raises a question), or cuts against (it disagrees with something we built). These are rules and studies of other people's apps. None of them is a study of Professor Oops, and we don't claim to comply with any law here; we read the rules and designed to them.
Always unfair: a direct exhortation to children in an advert to buy, or to persuade adults to buy. The reason for no "ask a grown-up" anywhere and for the tile's design.
Principle 7: design must respect children's vulnerabilities, and age gates and parental controls don't reduce that duty. The game has no virtual currency; we applied its reasoning, which is why a gate in front of a lure doesn't make it fair.
€1,125,000 in two fines for direct purchase pressure on children ("Get it now", "Buy now") and misleading countdown timers. The reason for no timers and no "only today".
Principle 4, commercial information clear and apart from gameplay; principle 6, with its example of an unhappy cartoon character used to push a purchase; principle 7, no direct exhortation. Why the welcome has no price and no character ever asks.
No direct appeal to children to buy; children must not be encouraged to copy unsafe practices. Used for the offer's wording and for store videos.
Defines nagging as a request "that doesn't let the user permanently decline", and parasocial relationship pressure. The reason every ask has "No thanks, don't ask again".
$275 million COPPA penalty and $245 million in refunds. Shaped the fixed order: the sum, an offer with the price, then the store's own sheet.
Kids Category rules on third-party analytics and ads (the text says "should not", with limited cases; the game has neither), and on never framing risky acts as a challenge.
Applied, with a deviation. "Adult-level tasks that must be completed." The gate exists; we made it easier than our own research asked, on purpose.
Rules on what may appear at launch, no emotionally manipulative offers, and monetisation kept distinguishable from play. The reason the first-launch welcome has no price.
Art. 20 bans loot boxes in games aimed at or likely to be used by children; art. 17 asks for tools to limit and monitor time of use. One fixed product, and the play-time limit.
133 apps played by 160 children aged 3 to 5; 26 of 133 (19.6 %) had none of the manipulative designs coded. Killed the locked present and the daily gifts. The authors call the socioeconomic results exploratory. doi:10.1001/jamanetworkopen.2022.17641
135 apps reviewed in all (a 39-app pilot and the 96 most downloaded in Google Play's "5 and under"); 129 (95 %) carried at least one kind of advertising. An exploratory study. doi:10.1097/DBP.0000000000000622
Found later: a caution. 295 children aged 5 to 8: the game raised brand preference among older children only, and made no difference to intention to ask for the product. The science of pester power is less settled than the law's position; we follow the law. doi
Found later: fits. 209 children aged 8 to 12: understanding grows from 8 to 12, with a clear rise around 10. Backs treating our audience as not yet equipped; under-8s weren't studied. doi
Why the counts start off across most of the EEA.
Recital 58 asks for language a child can understand: the privacy page's "For children" box.
An internet address is a persistent identifier; it is used only for internal operations, as the privacy page says.
The store label for the counts: Usage Data, Product Interaction, not linked to the user.
Found later: fits. 5,855 popular free children's Android apps; a majority potentially in violation, mainly through third-party SDKs. Fits the choice of no SDKs; it is about other apps, not an audit of ours. doi
Found later: raises a question. 27 parents interviewed and 28 families' diaries, children 1 to 5: transitions ended by technology went better than parent-ended ones, and parents' two-minute warnings made things worse. Our warning comes from the device, and our players are older; the question stays open. doi
Found later: fits, in part. 8.4.1: slide the lid over, turn off the burner, leave it until cooled; 8.4.2: never pour water on it. Matches the lid and no water. It says nothing for the towel on pan fires.
Found later: fits, in part. Turn off the heat, cover the pan with a lid, a baking tray or a sturdy tray, never use water. Matches the lid and no water; it mentions no cloth.
Cuts against. "Never throw water or a damp tea towel over it." Contradicts the game's "Damp tea towel" button. One regional service's release; the others above are silent on towels.
Found later: fits. Don't mix cleaning products; bleach with some cleaners releases chlorine; get to fresh air. Matches the game's chlorine line.
Found later: fits in shape. 60 children aged 5 to 8: dangerous behaviour, its consequence, then the safe behaviour lowered willingness to take risks and raised hazard identification. Self-report, short term; in our game nobody gets hurt. doi
Cuts against the comfortable story. 50 children aged 6 to 9: high-risk television raised self-reported willingness to take physical risks. Why "it stays on screen" is our rule, not a finding. doi
Found later: cuts both ways. 108 preschoolers generalised more from stories whose world resembled reality. Realism may help a safety line travel, and other cause and effect too. doi
