Applies to the mobile game Boomstack
(io.nestengineering.boomstack) on Android and iOS.
Last updated 17 October 2026.
Boomstack has no accounts and no sign-up. We never ask for your name, your email address or your phone number, and the game never asks your device where you are. We do work out roughly which country you are in from your internet connection. What the game sends is listed below in full.
Boomstack is made by Nest Engineering, the data controller for the purposes of the GDPR. For any privacy question, or to exercise any of the rights described below, write to support@nestengineering.io.
The save file itself never leaves your device. Your progress — levels cleared, stars, coins, boosters, settings and language — is written to the app’s own storage. There is no cloud save, we hold no copy, and we cannot restore it for you. Deleting the app deletes it permanently.
That is not the same as saying none of those numbers are ever sent. The analytics events described below carry some of the same values — how far you have unlocked, your coin balance after a change, the stars and coins from a level you just finished. They travel as individual events tied to a random installation identifier, not as a copy of your save, and they cannot be turned back into one. We would rather say this plainly than let “stored only on your device” do work it cannot do.
| Data | Why | Who receives it |
|---|---|---|
| Gameplay events App launches and session length, levels started, won and failed, stars earned, shots taken, your coin balance and what changed it, how far you have unlocked, whether you have removed ads, shop and ad interactions, app version, platform (Android/iOS), the game’s language, and your device’s regional locale (for example en_GB), which is the region you have set on
your device. |
To understand which levels are too hard, where players stop playing, and whether a change made the game better or worse. | Mixpanel |
| Approximate location The country, region and city your internet connection appears to be in. When an event reaches Mixpanel it uses the IP address that event arrived from to work out approximately where it came from, and stores that approximate location on the event. The game never reads your device’s location, never asks for a location permission and never sees GPS — there is no location API anywhere in it, and nothing is located to a street or an address. |
To know which countries our players are in. Everything that tells us whether the game can pay for itself — what an ad is worth, what a player spends, whether a launch in one country worked — is a per-country number. | Mixpanel |
| An installation identifier A random string the app generates the first time it runs, stored with your saved game. |
To tell one player’s events apart from another’s without knowing who either of them is. The same identifier is attached to crash reports, so a crash can be matched to the session it happened in. | Mixpanel and Sentry |
| Crash and performance reports The error, a stack trace, device model, OS version, app version, your language setting, and the installation identifier above. The app’s own log file is attached to every report, along with the level you were playing and a short trail of the levels you started, won or failed just before it happened. That log records what the game did, not what you typed or who you are. No name, no email, and no IP address — the SDK’s personal-data option is left off, so crash reports are not located even approximately, unlike the analytics events above. |
To find and fix crashes, and to see how many players one crash affects. | Sentry |
| Advertising data Handled by Google’s ad SDK and, on Android, by the SDK of whichever partner network’s ad is shown (see Advertising and your consent). May include your device’s advertising identifier, IP address, device and OS information, and which ads you were shown — subject to your consent choices, see below. The game also asks for your year of birth once, and sends Google a yes/no age category derived from it (whether you are below the age of consent for advertising). The year itself is never stored or sent — only the yes/no. |
To show ads, to cap how often you see them, and to measure them. | Google AdMob; on Android also Unity Ads and Mintegral |
| Install attribution When you first open the game we send an installation record so we can tell which advertisement brought you here. On iOS this includes your device’s advertising identifier (IDFA) only if you allowed tracking when asked; on Android it is the advertising ID, which you can reset or limit in your device settings. It also includes the installation identifier described below, your device and OS information, and your IP address. Afterwards we send the same service a short list of milestones — the first time you win each level, with the level’s number and how many stars you earned, and finishing the tutorial — so the advertising networks we buy from can tell whether their advertisements bring players who actually play. AppsFlyer’s answer — whether the install came from an advertisement, and which advertising source and campaign — is also recorded in our own analytics (Mixpanel), so we can compare how players from different campaigns play. When this happens: never before the age question is answered, and in places where the game shows a consent form (such as the EEA and the UK) only once you have completed that form. Completing it is what starts this, whichever way you answered: the choices you made in it are passed to AppsFlyer, which has to respect them. Where no form is shown, it starts by default. Changing your answers later in the game’s privacy settings updates what AppsFlyer is allowed to do with this data — your new choices are passed on to it — but does not by itself switch install attribution off. To have what AppsFlyer holds about your installation deleted, use the contact under Your rights below. |
To know which advertisement or campaign an install came from, and to measure whether our advertising is worth buying. | AppsFlyer |
| Purchase events Which product, the price as your store displays it, whether the purchase completed, failed or was restored, the reason for a failure, and the store’s transaction id. Attempts that fail or that you cancel are recorded too. Never your card number, billing address or store account. |
To deliver what you bought, and to find out where purchases break. | Apple / Google, RevenueCat, and Mixpanel. RevenueCat keeps your purchases under a random identifier it creates for your installation — not your name, email or store account — which is how a purchase is recognised again when you restore it. Linking purchases to advertising: so that the advertisement that brought you can be credited with a purchase, we give our purchase provider (RevenueCat) AppsFlyer’s identifier for your installation together with your device’s advertising identifier, and RevenueCat then reports your purchases to AppsFlyer. This is done when you start the game, before any purchase. On Android it happens whenever install attribution (the row above) is running, so by default where no consent form is shown. On iOS it happens only if you allowed tracking when asked; if you did not, neither identifier is given to RevenueCat and your purchases are not reported to AppsFlyer. On iOS, turning tracking off in your device settings removes the link the next time you open the game. On Android there is no equivalent switch: you can reset or delete your advertising ID in your device settings, and you can ask us to have the data deleted (see Your rights below). |
It is a random value created by the app itself on first launch and kept inside the game’s own save file. It is not your device’s advertising ID, not a hardware serial, and not shared with any other app. Uninstalling Boomstack destroys it; reinstalling produces a new, unrelated one.
Boomstack shows ads between some levels, and optional ads you choose to watch in exchange for a reward. Ads are served by Google AdMob.
On Android, AdMob also lets two other ad networks bid to fill the same ad slots: Unity Ads (Unity Technologies) and Mintegral (Mintegral International Limited). Each has its own SDK inside the game. When one of them wins, its SDK loads and shows the ad and receives the advertising data described above; it also receives data about the device and the ad request while bidding. Neither starts before the age question is answered, and the game passes each of them the same choices it gives Google: your answer in the consent form in the EEA, the UK and Switzerland, a do-not-sell signal for players in the United States, and, for players aged 13 to 15, that ads must not be personalised. On iOS only Google AdMob is used.
Google’s handling of this data is governed by the Google Privacy Policy and how Google uses data from apps that use its services. Unity’s and Mintegral’s handling is governed by their own privacy policies, linked under Third-party services below.
All payments are taken by Apple or Google. We never see or receive your card number, your billing address or your store account details — those never reach us or the game. What we do record is listed in the table above: the product, the displayed price, the outcome, and the store’s transaction id, including for attempts that fail.
Being precise about analytics, because it would be easy to imply otherwise: analytics and crash reporting are not behind the advertising consent form, so declining that form does not switch them off. They are behind the age question the game asks on first launch: until you answer it, and unless the answer allows the game to open, nothing is collected, no installation identifier is created and nothing is sent anywhere — see Children below. You can object to this processing at any time under Art. 21 by writing to us, and uninstalling the game stops it outright.
Analytics events are retained by Mixpanel for up to 12 months. Crash reports are retained by Sentry for up to 90 days. Advertising data is retained by Google, Unity and Mintegral under each one’s own retention policy. AppsFlyer and RevenueCat keep what they receive under their own retention policies, linked under Third-party services below; we do not set a shorter period with either of them. Data on your device is kept until you delete the app.
If you are in the EEA, the UK, Switzerland, California or another region with comparable law, you have the right to access, correct, delete, restrict, port or object to the processing of your personal data, and to withdraw consent at any time.
To exercise any of these, email support@nestengineering.io and tell us your device model and roughly when you installed the game. We respond within 30 days. You also have the right to complain to your local data protection authority.
Please understand the limit this creates. We hold no account for you and the installation identifier exists only inside the app on your device, so we have no reliable way to match a request by email to a particular set of analytics events. This is a consequence of collecting as little as we do, not an evasion — and it is why the most complete deletion available to you is to uninstall the game. Doing that destroys the saved game, the installation identifier, and the link between you and the analytics and crash data already collected.
One thing uninstalling does not undo. If install attribution was running (see What the game sends), AppsFlyer holds the installation record. If your purchases were also linked to it — on Android whenever attribution was running, on iOS only if you allowed tracking — our purchase provider holds AppsFlyer’s identifier for your installation on its own servers as well. None of this is on your device, so removing the game cannot erase it. (Boomstack sells no subscription, so nothing new is reported after the game is gone — but what was already recorded stays until it is deleted.) To have these deleted, email us as described above and say that you want your attribution and purchase-provider data removed; include the approximate date you installed the game and, if you made a purchase, its date, so that the record can be found.
Boomstack is not directed to children under 13 (or the equivalent minimum age in your country), and it is not enrolled in Google Play’s Designed for Families programme.
On first launch the game asks for your year of birth. The year itself is not stored and is not sent anywhere; only the yes/no answers derived from it are kept on the device.
If you are a parent and want a child’s data removed, email support@nestengineering.io; deleting the app stops any collection immediately.
Our service providers process data in the United States and the European Union; Mintegral, an advertising partner on Android, is based in Hong Kong and processes data in its own locations. Where data leaves the EEA it is transferred under the European Commission’s Standard Contractual Clauses or an adequacy decision.
If we change what the game collects, we will update this page and change the date at the top. Material changes will also be announced in the app.