Stack Up

Privacy

Last updated 27 September 2026

Stack Up is a stacking game for iPhone, made by Reynaldo Columna at Overlaydeck. This page says, in plain words, what the app keeps, what it sends, and who it sends it to.

The short version

• No account. No name, email, phone number or password is ever asked for.
• Your progress lives on your phone.
• The app sends anonymous gameplay and crash reports to Google Firebase.
• Ads come from Google AdMob. You choose whether ads may use your advertising identifier.
• If you use Game Center, your daily points and achievements go to Apple.

What stays on your phone

The game saves these in its own storage on your device:

• Your progress: levels cleared, stars, coins, power-up charges, block skins, achievements and today's points.
• What you have bought, such as Remove ads, plus the store receipt numbers used to make sure a purchase is only credited once.
• Your settings, such as sound and vibration.
• Small notes like whether you have already been asked to rate the game.

None of this is uploaded to us. There is no cloud save and no server copy of your progress.

Gameplay and crash reports

The app uses Google Firebase Analytics and Firebase Crashlytics, so we can see where players get stuck and fix what breaks.

• Gameplay events. When you start, clear or fail a level (with the level number, stars and coins earned), open the shop, or complete a purchase (which product).
• Crash and error reports. When the game hits an error or crashes, a report with the error message goes to Crashlytics.

Firebase also records standard technical details on its own, such as your device model, iOS version, app version, rough region, and a random ID for this install of the app. None of it includes your name or contact details. Google handles this data under its own terms, at firebase.google.com/support/privacy.

Game Center

When the app opens, it asks Apple's Game Center to sign you in. That is Apple's own sign-in, not an account with us, and you can ignore it. If you are signed in, each level you clear sends your points for the day to Stack Up's daily Game Center leaderboard. Apple shows that score with your Game Center name to other Game Center players. Your achievement progress (for example "5 perfects in a row") is sent to Game Center too, so it shows in Apple's own achievements list. Apple runs Game Center under its own privacy policy.

Today's board

The leaderboard inside the game is you against practice rivals the game generates on your phone each day. They are not real people, and your score on that board is never sent anywhere.

Advertising

Stack Up is free and is paid for by ads from Google AdMob. The first releases ship with ads switched off while Google reviews the app: until an update turns them on, the app shows no ads, loads nothing from AdMob and asks nothing about tracking. Once they are on, you get:

• a banner at the bottom of the screen while you play a level,
• a full-screen ad now and then when you move on after clearing a level (never in your first few levels, and not more than about once every three levels),
• videos you choose to watch, to double the coins from a win or to get slow-mo for a few blocks (up to five a day).

Google picks which ad you see. To do that it may use your device's advertising identifier, your rough location, your device type and which ads you have seen. We never see that data. Google explains its use at policies.google.com/technologies/partner-sites.

Your choice. Before any ad loads, the app runs Google's consent step. Where the law requires it (for example in the UK and EU), that shows a consent form, and a Privacy choices row in Settings lets you change your answer later. iOS then asks whether Stack Up may track you. Say no and you still see ads, just less targeted ones. Nothing in the game changes. You can change this any time in iOS Settings, under Privacy & Security, then Tracking.

Or remove them. Remove ads is a one-time purchase that turns off the banner and the between-level ads for good. The videos you choose to watch stay available.

Purchases

Purchases are handled by Apple. We never see your card, billing address or Apple ID. The app is only told that a purchase went through, so it can hand over the coins or the unlock.

What we never collect

No name, email, phone number, contacts, photos, microphone, camera or precise location. There is no chat and no way for players to message each other. We do not sell your data.

Children

Stack Up is not directed at children under 13. It shows ads chosen by Google and sends the reports described above. We do not knowingly collect anything from children under 13. If you think a child under 13 has been playing, email us.

Deleting your data

• On your phone: delete the app. That removes your progress and settings for good. Reset progress in Settings clears your levels, stars and earned coins but keeps Remove ads, block skins, achievements and unspent coins you bought.
• Game Center: scores and achievements sent to Apple are managed by Apple, in your Game Center settings.
• Analytics and crash reports: these carry no name or email, so we usually cannot match them to you. Email us anyway and we will do what we can.
• Ads: reset or limit your advertising identifier in iOS Settings, under Privacy & Security.

Changes

If Stack Up starts doing something this page does not describe, this page changes first, and the date at the top changes with it.

Contact

Questions or requests: hello@overlaydeck.com