Privacy Policy — BrainShield

BrainShield Privacy Policy

Last updated: July 19, 2026

App name: BrainShield

Developer: Ciertolab

Package name: com.ciertolab.focusguard

Contact: appattitude911@gmail.com

BrainShield is a personal content-filtering app that runs entirely on your device. This policy explains what the app does and does not do with your data, and why it requests the permissions it does.

What BrainShield does not do

  • It does not collect, transmit, sell, or share any personal data.
  • It does not have a backend server, account system, or cloud sync.
  • It does not read, store, log, or transmit the content of your screen, your messages, your browsing history, or your DNS queries.

Information we collect

BrainShield does not collect any personal information. The app runs entirely on your device and does not transmit user data to us or any third party, with the following limited exceptions described below.

Permissions and what they're used for

Accessibility Service

BrainShield uses Android's Accessibility API for two purposes, both of which run entirely on your device:

  • Content filtering: detecting when specific screens are open in apps you've chosen to restrict (the Reels tab in Instagram/Facebook, the Shorts player in YouTube, NSFW content in Reddit, or any adult content in web browsers), and performing a "back" action to close them. This requires reading on-screen text and layout identifiers, but only within those specific apps.
  • Heavy Focus Mode app lock: if you choose to lock specific apps while Heavy Focus Mode is on, detecting when a locked app is opened and sending you back to your home screen instead. This only requires knowing which app is currently in the foreground — it does not read that app's on-screen content. Because a locked app can be any app you choose, the Accessibility Service receives foreground-app events from every app, not just the ones listed above, so it can recognize a locked app opening no matter which one it is.

In both cases, BrainShield does not read, store, or transmit any content it observes beyond what's described above, and nothing is ever written to disk or sent anywhere. On-screen content is only read for the specific content-filtering screens listed above — for every other app, BrainShield only ever knows its package name (i.e. which app it is), never what's displayed inside it.

Device Admin (uninstall protection)

If you turn on Heavy Focus Mode, BrainShield can optionally ask to become a device administrator using Android's Device Admin API. This is used solely to prevent the app from being uninstalled through the normal Settings flow while Heavy Focus Mode is on, adding friction against an impulsive decision to quit. It is requested only when you explicitly choose "Protect from uninstall" — it is never required to use Heavy Focus Mode or any other feature. It can be turned off at any time by disabling Heavy Focus Mode from inside the app (which removes the device admin automatically) or, if needed, directly from your device's Settings > Security > Device admin apps. BrainShield does not use this permission to lock your device, wipe data, enforce a password policy, or restrict anything other than its own uninstallation.

Display over other apps

BrainShield may request permission to draw over other apps (Android's "SYSTEM_ALERT_WINDOW") for two purely cosmetic, on-device purposes: briefly flashing a "Blocked" message after closing a filtered screen, and showing a short instructional card over Android's own Settings screen to help you find the right toggle while granting Accessibility or Device Admin permissions. This permission is optional — if not granted, both features silently do nothing and the rest of the app works normally. Nothing about what's on your screen is read, stored, or transmitted through this permission.

VPN Service (local, on-device only)

When you enable the adult-content blocking filter, BrainShield starts a local VPN tunnel using Android's VpnService API. This is not a traditional VPN: no traffic is ever sent to a remote server. The tunnel only intercepts DNS lookups (UDP port 53) so that known adult-site domains can be blocked at the resolution stage. Every other kind of network traffic bypasses the tunnel entirely. DNS lookups for domains that are not on the blocklist are forwarded, unmodified, to a public DNS resolver (Cloudflare, 1.1.1.1). Those lookups are not logged or stored by BrainShield.

Network access (blocklist download)

To keep the adult-site blocklist current, BrainShield downloads a public, third-party-maintained list of domains (the StevenBlack/hosts "porn-only" list) over HTTPS. This is a one-way download: the request does not include your DNS queries, browsing history, device identifiers, or any other data. If the download fails, BrainShield uses the last successfully downloaded copy instead.

Notifications

BrainShield shows a persistent, low-priority notification while the VPN filter is running, as required by Android for any foreground service. This notification does not contain any personal information.

If none of BrainShield's protections are currently active, the app may also show one local notification per day with a short motivational message encouraging you to turn a filter back on. This check runs entirely on your device using Android's WorkManager: it only reads your own locally-stored switch preferences to decide whether to show it, the message is chosen from a fixed, built-in list of 25 messages, and nothing about your device or usage is read, stored, or transmitted to schedule or generate it. You can turn this off at any time from your device's system notification settings for BrainShield.

Advertising

BrainShield displays banner ads provided by Google AdMob. As part of serving ads, AdMob may collect and process certain device information (such as your device's Advertising ID / GAID, IP address, and device type) in accordance with Google's Privacy Policy. You can learn more about how Google uses this data at https://policies.google.com/privacy.

You may opt out of interest-based advertising at any time by visiting your device's Google Settings > Ads > Opt out of interest-based ads.

Data retention

BrainShield stores your switch preferences (which filters are on/off), whether Heavy Focus Mode is on, and which apps you've chosen to lock — all locally on your device using Android's DataStore. None of this is ever transmitted anywhere, and uninstalling the app removes it. The one-time code used to disable Heavy Focus Mode is generated fresh on your device each time you try to disable it and is never saved by the app. Whether uninstall protection (device admin) is currently active is read directly from Android's own system state each time it's needed, not stored separately by BrainShield.

Third-party services

BrainShield uses the following third-party services, each of which operates under its own privacy policy:

Changes to this policy

If BrainShield's data practices change, this document will be updated accordingly and the "Last updated" date at the top will be revised.

Contact

If you have any questions about this privacy policy, please contact us at:

BrainShield — Developed by Ciertolab
Package: com.ciertolab.focusguard
© 2026 Ciertolab. All rights reserved.