Explicit images get covered before your child sees them.
SentryScreen is a background app for your family's Mac. It looks at what is on the screen, on the Mac itself, and puts a solid cover over explicit content — in any app, any browser, any window.
Screen content never leaves the Mac. Frames are examined in memory and discarded. No images are uploaded, stored, or sent to us, and there is no analytics service of any kind.
The one thing SentryScreen does send is a small subscription and update check, about every six hours. Here is every field it contains.
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What it does
SentryScreen watches the Mac's screen and covers explicit images as they appear. The cover is a plain solid rectangle — nothing shows through it, and it moves and resizes with the window underneath.
It works the same everywhere on the Mac: a browser tab, a chat app, a video, a document, an app we have never heard of. It does not depend on a list of blocked websites, so it is not defeated by a new site or a private window.
Install it once, from an administrator account. It then runs in every account on that Mac, including your child's Standard account, and starts again at every login.
Setting it up: three things you do
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Install it
Download the installer and run it from an administrator account on the Mac.
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Approve one macOS permission
macOS requires you to turn on Screen Recording for SentryScreen by hand, in System Settings. We cannot turn it on for you. Setup shows you exactly where the switch is.
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Set a parent PIN
The PIN protects pausing and settings, so the controls stay with you. Protection starts as soon as this is done.
Your subscription email carries an activation link. Click it once on the Mac, whenever it suits you, and the Mac is licensed. It is protecting your child before then, and keeps doing so if the email is slow to arrive.
What leaves the Mac
About every six hours, a background system service sends one small message to our server, to check your subscription and to ask whether there is an update. It contains:
- your license key;
- a random identifier we generated for this installation the first time it ran — a random number, not your Mac's serial number and not anything your Mac already had;
- the SentryScreen version and build number;
- your macOS version, to the minor version only (for example “15.4”);
- the processor family (for example “arm64”);
- which update channel this installation follows.
That is the complete list. No screen content, no detection results, no images, no application names, no window titles, no log files and no diagnostic data are ever sent — not on this request and not on any other.
The part of SentryScreen that looks at the screen makes no network request of any kind, and your child's account makes none either. The privacy statement spells all of this out, including what our server keeps and for how long.
Honest limits
This matters more than a feature list, so it is on the page rather than in the small print.
- It can miss things, and it can cover harmless things. It is a detector, not a person. Expect it to let something through occasionally, and to cover the odd beach photo or medical diagram. It is one layer of protection, not a replacement for knowing what your child is doing.
- You have to grant the permission yourself. macOS will not let us turn on Screen Recording for you, and it may ask you to confirm it again after a macOS update. If the permission is missing, SentryScreen tells you instead of pretending to work.
- macOS 14 Sonoma, 15 Sequoia and 26 Tahoe, on Apple silicon. Intel Macs are not supported.
- It covers what is on screen — that is all it does. It does not block websites, filter downloads, restrict apps, or read messages.
- It does not save screen images. On that Mac, you can see when a cover appeared and which app it was in. The pictures themselves are never written down.
Pricing
One subscription covers your household. Cancel at any time.
- Up to 3 Macs.
- As many child accounts as you like on each Mac, at no extra cost.
- Every update, including improvements to the detector.
- Support by email: support@sentry-screen.com.
If your subscription lapses
SentryScreen keeps protecting your child. If a payment fails you get a reminder on the Mac and an email once a day for seven days; after that a renewal notice stays in the app until you renew. Protection and updates carry on the whole time. Nothing about billing switches protection off — not a failed card, not a cancellation, not our server being down.
Download
The installer is the same for everyone; your subscription email carries the link that activates this Mac.
- macOS 14 or later, on an Apple silicon Mac.
- An administrator account on the Mac to install it.
- Already subscribed and lost the email? Have it sent again.
Questions
What permission does it need, and why?
One: Screen Recording. It is how macOS lets an app see what is on the screen, which is the whole job. macOS requires a person to grant it in System Settings › Privacy & Security, so you do it by hand during setup. Nothing is recorded — the name of the permission is Apple's, not a description of what SentryScreen does.
Does it work in my child's account?
Yes. You install it once from your administrator account and it runs in every account on that Mac. There is no limit on how many child accounts a Mac has. A Standard account cannot see the settings, the PIN or your license, and never makes a network request.
Can my child turn it off?
Not from a Standard account: pausing and settings are behind your PIN, and the background jobs need administrator rights to stop. Anyone with the Mac's administrator password can remove SentryScreen — that is how macOS works, and it is why the administrator password should be yours alone.
What data do you collect?
From the app: the six items listed under what leaves the Mac, and nothing else. We never receive screen content, detection results, application names, window titles or logs. Our server sees the internet address a request came from, as any server does; we use it only to limit abuse, do not store it and never attach it to your license. Full detail is in the privacy statement.
How many Macs does one subscription cover?
Three, with unlimited child accounts on each. If you set it up on a fourth Mac it still protects that Mac, and tells you that you are over the limit rather than shutting anything off.
How do I cancel or change my card?
Through your subscription page, which opens the Stripe customer portal. Enter your email, Stripe emails you a login link, and you can cancel, switch between monthly and yearly, or update your card there. Cancelling takes effect at the end of the period you have paid for.
What is your refund policy?
Cancelling stops the next charge; we do not refund part of a period you have already paid for, except where the law requires it. The full terms are in the license agreement, section 3. If something is wrong with the product, email support@sentry-screen.com and we will sort it out.
How do updates work?
They install themselves in the background, so you do not have to think about them. Before anything is installed, SentryScreen checks that the package matches the checksum our server gave and that Apple's signature checks pass; if a check fails, nothing is installed. If protection does not come back after an update, the previous version is put back automatically.
Will it work on an Intel Mac?
No. SentryScreen supports Apple silicon Macs on macOS 14, 15 and 26. We would rather say so here than after you have paid.