Legal

Privacy Policy

Effective date: October 2, 2026

Applies to Mind Stack, a collection of brain games for Android published by Evernile Studio.

1. Introduction

This Privacy Policy explains how Evernile Studio ("Evernile," "we," "us," or "our"), formerly operating as Mobitech, handles information in connection with our Android app Mind Stack (the "App"). The App is a collection of brain games, such as Fifteen Puzzle, Number Rush, Stroop Effect, and Tiles. We may add, change, or remove games over time. This policy applies to every game included in the App, now or in the future.

The App does not require an account, does not show ads, and does not use analytics or tracking for advertising or marketing. The App is built with the Unity engine, which sends limited crash and diagnostics data to Unity so we can find and fix problems (see Section 2.4). This policy explains what information is involved when you play and when you choose to contact us.

By downloading or using the App, you agree to the practices described in this Privacy Policy. If you do not agree with this policy, please do not use the App.

2. Information We Collect

2.1 What we do not collect

The App does not include any analytics or advertising service. As a result:

We do not require you to create an account or sign in.
We do not track your behavior across other apps or websites.
We do not serve advertising, and we do not collect advertising identifiers (such as your device's Advertising ID).
We do not collect usage analytics, such as which screens you visit or how long you play.
We do not collect your location, contacts, photos, or any other personal content on your device.

2.2 Game data stored on your device

Your progress and settings in every game in the App, such as scores, best times, levels completed, and your in-app preferences, are stored locally on your device only. This data is never sent to us or to any third party. Apart from the crash and diagnostics data described in Section 2.4, the only information that reaches us is what you choose to send in an email (see Section 2.3).

2.3 Information you send us by email (feedback and contact)

The App includes two email options, Feedback and Contact Us. When you use either one, the App opens your device's email app and pre-fills a draft message addressed to us. Nothing is sent unless you choose to tap Send in your email app. You can review, edit, or delete any part of the draft before sending it.

The draft includes the following technical details to help us understand and fix any issue you report:

App version: the version number of the App you are using.
Device details: your device manufacturer and model.

These details do not include your name, contact details, or any unique device or advertising identifier.

If you send the email, we will also receive your email address, any name associated with your email account, and anything you write in the message or attach to it.

We use this information only to reply to you, investigate issues you report, and improve the App. We do not use it for marketing, and we do not sell or share it with third parties. Your email itself is delivered and stored by your email provider and by our email provider (Google Gmail), under their own privacy policies.

2.4 Crash and diagnostics data (Unity Diagnostics)

The App is built with the Unity engine and uses Unity Diagnostics, a crash and error reporting service provided by Unity Technologies. When the App runs, and especially when it crashes or hits an error, Unity Diagnostics automatically collects:

Crash logs and error reports;
App diagnostics and performance data, such as the App version and technical details about the error;
Device information, such as device model and operating system version; and
A random installation ID that Unity creates for each installation of the App. It is not your name, email address, or advertising ID.

We use this data only to find and fix crashes and errors. It is not used for advertising, it is not shared with or sold to third parties, and it is encrypted in transit. Unity processes this data on our behalf and keeps it for 90 days, after which it is deleted automatically. This data collection is required for the App to work as intended and cannot be turned off in the App.

3. App Permissions

The App requests only the following device permissions. Both are standard permissions that Android grants at install time; the App never asks you to approve access to personal data such as your location, camera, microphone, contacts, or files.

Permission	Why the App uses it
`android.permission.INTERNET`	Lets the App download its configuration file and the list of our other games and apps shown in "More Games / Apps" (Section 4.2), and send crash and diagnostics reports to Unity (Section 2.4). It is not used for advertising.
`android.permission.VIBRATE`	Provides short haptic feedback during gameplay, for example on a correct or incorrect answer.

4. Third-Party Services

We do not sell, rent, or share your personal information with third parties for advertising, marketing, or other commercial purposes. The App does not integrate any third-party advertising, analytics, or data-broker SDKs. The App relies on the following services.

4.1 Unity Diagnostics (Unity Technologies)

Unity Technologies provides the Unity engine and the Unity Diagnostics service described in Section 2.4. Unity processes this data on our behalf. See Unity's Game Player and App User Privacy Policy for details.

4.2 Configuration service (Netlify)

The App downloads a static configuration file hosted by Netlify, Inc. The request sends no parameters and no personal information. The file contains only general settings that are the same for every user, such as the list of our other games and apps and whether an App update is available. The names and icons shown in the "More Games / Apps" dialog are also loaded from Netlify. This list may change over time as we publish new games and apps.

Like any web server, Netlify's hosting infrastructure may process standard technical information that comes with a network request, such as your IP address and request details, in order to deliver and secure these files. We do not use this information to identify or track you. See Netlify's Privacy Statement for more information.

4.3 More Games / Apps, Rate Us, and store links

When you tap More Games / Apps, the App shows a dialog listing other games and apps from our studio. Opening this dialog does not send any information about you to us. When you tap Get next to a game or app, the App opens that game's or app's page directly in the app store (such as Google Play).

Rate Us: The first time you tap Rate Us, the App asks Google Play to show its in-app review window, so you can rate the App without leaving it. This window is displayed and handled entirely by Google Play. We do not receive your rating or review through the App, and Google Play decides whether the window appears. If you tap Rate Us again later, the App opens the App's page in the store directly. Ratings and reviews you submit are published by Google Play under its own terms, along with your Google Play profile name.

The App does not track which games or apps you view or tap in this dialog. Once the store opens, the store's own privacy policy applies, for example Google's Privacy Policy for Google Play.

If we add a new third-party service in a future update, we will update this Privacy Policy and, where required, the App's Google Play Data safety disclosures before the change takes effect.

5. Children's Privacy

The App is intended for users aged 13 and older and is not directed at children under 13. We do not knowingly collect personal information from children under 13. If you believe a child under 13 has sent us personal information, for example in a feedback email, please contact us and we will delete it.

6. Data Retention and Deletion

6.1 Game data on your device

You can delete your locally stored game data at any time by:

Using the Delete My Data option in Settings. To prevent accidental deletion, you will be asked to type delete in the text field and confirm. This permanently clears your progress and scores for every game in the App and cannot be undone;
Clearing the App's storage from your device settings; or
Uninstalling the App.

Because this data is stored only on your device, we cannot see it, back it up, or restore it once it has been deleted.

6.2 Crash and diagnostics data

Crash and diagnostics data (Section 2.4) is linked only to a random installation ID, not to your name or email address. The current version of the App does not show this ID, so we are not able to find and delete an individual user's diagnostics data on request. This data is deleted automatically by Unity 90 days after it is collected. We plan to add a way to request deletion of this data in a future update.

6.3 Feedback and contact emails

We keep feedback and support emails so we can follow up on issues and understand past reports. If you want your emails with us deleted, email us from the same address and ask. We will permanently delete those emails and all information they contain, including the app and device details described in Section 2.3.

7. Your Rights

Depending on where you live, you may have the right to access, correct, or delete personal information we hold about you, or to object to how we use it. In practice, the personal information we hold is what you send us by email and the crash and diagnostics data described in Section 2.4. To make a request, contact us at the address below.

8. Security

Game progress stays on your device and is protected by your device's own security. Crash and diagnostics data is encrypted in transit and stored by Unity. Emails you send us are stored in our Google-hosted email account, which is protected by standard account security measures. No method of transmission or storage is completely secure. We recommend keeping your device's operating system up to date and using a screen lock.

9. Changes to This Privacy Policy

We may update this Privacy Policy from time to time, for example when we add a new game or a feature that changes what data the App uses. The "Effective date" at the top of this page shows the date of the latest revision. Please review this page periodically.

10. Contact Us

If you have any questions about this Privacy Policy, want to request deletion of your emails, or want to ask how the App works, contact us at:

evernilestudio@gmail.com