Privacy policy

Effective 28 October 2026

The short version

• GrabStack reads only the screenshots on your phone. Your library, stacks, Want list, the text read from your screenshots and your settings are kept in a database on your phone.
• There is no account, no advertising, no tracking and no analytics of how you use the app.
• Stack suggestions are the only feature that sends screenshots off your phone. They are off until you agree. Then only the screenshots you pick are sent, as smaller copies, to Claude, an AI model made by Anthropic. Pro has an automatic suggestions setting for new screenshots, which is off until you switch it on and agree to it separately.
• Our server keeps a random install ID and simple counters so we can apply the monthly allowance, prevent abuse and check whether you have Pro. It does not keep your screenshots.
• You can delete everything GrabStack stores on your phone with Delete all GrabStack data in Settings, or by deleting the app. Your screenshots in Photos are not touched.

1. Who we are

GrabStack is a screenshot organiser for iPhone and Android. It is published by the developer named as the seller on its App Store and Google Play pages, referred to here as “we” or “us”. We are the controller of the personal data described in this policy under the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018. You can reach us using the details in Contact us.

2. What GrabStack reads on your phone

GrabStack asks for permission to see your photos so it can show and organise your screenshots. It only reads screenshots. It does not read your other photos, your videos or the location stored in your photos.

• On iPhone, iOS asks for access to your photo library because it has no screenshots-only permission. GrabStack then reads only the items that iOS marks as screenshots.
• On Android, GrabStack asks for permission to read images and only reads the images in your phone's Screenshots folders. If your phone has no Screenshots folder, GrabStack looks at the names of your images to find the ones that are screenshots, and keeps nothing about the others.
• If you choose to give access to selected photos only, GrabStack works with the screenshots you selected. You can change this at any time in your phone's settings.

GrabStack only deletes a screenshot from your phone when you ask it to, for example in Clean up. On iPhone, and on Android 11 and later, your phone shows its own confirmation before anything is deleted. Android 10 and older have no such confirmation, so on those phones GrabStack shows its own confirmation first.

3. What stays on your phone

GrabStack keeps the following in a database inside the app on your phone. None of it is sent to us.

• Your library: a list of your screenshots with their dates and sizes, so the app can show them quickly. The screenshots themselves stay in your phone's photo library.
• Your stacks, your Want list and any notes or reminders you add.
• The text in your screenshots, which GrabStack reads on your phone so you can search it. On iPhone this uses Apple's built-in text recognition. On Android it uses Google's ML Kit library, which also runs on your phone (see below).
• The titles and keywords that stack suggestions return, if you use them.
• Your settings, including whether you have agreed to stack suggestions and to automatic suggestions, and the random install ID described in section 5.

GrabStack also keeps some files in its own storage on your phone: the smaller copies it makes for stack suggestions, thumbnails, and the copies and collages it makes when you share a stack. None of these files are sent to us, apart from the smaller copies you send for stack suggestions as described in section 4.

ML Kit on Android. ML Kit reads the text on your phone and does not need an internet connection to do it. Google says the library sends Google basic diagnostic information, such as the device model, app and library versions, performance figures, error codes, the size of the images processed and an identifier for the library on that installation, which Google uses to monitor and improve ML Kit. Google's ML Kit data disclosure lists exactly what is sent. Your screenshots and their text are not on that list.

Your phone's own backup, such as iCloud Backup or Google backup, may include this database depending on your phone's settings. That backup is handled by Apple or Google under their own privacy policies, not by us.

4. Stack suggestions (AI Sort)

Stack suggestions are optional. They are switched off until you agree to them on a screen that explains what will be sent. You can switch them off again at any time in GrabStack's Settings.

What is sent

When you pick some screenshots and tap to sort them, GrabStack sends:

• the screenshots you picked, made smaller on your phone first (at most 768 pixels on the longest side) and saved as JPEG images, up to 10 at a time;
• the names of your existing stacks, so the suggestions can reuse them;
• the random install ID and the app's version number.

Each image is labelled with a temporary number that only means something within that one request, not with anything that identifies the screenshot on your phone. Nothing else from your library is sent.

Automatic suggestions (Pro)

GrabStack Pro has an optional setting that suggests stacks for new screenshots automatically. It is off by default for everyone, including people who have Pro. Switching it on needs its own separate agreement: GrabStack shows a screen that explains that new screenshots will be sent to Claude for suggestions as they arrive, and nothing is sent automatically unless you agree there. It also only works after you have agreed to stack suggestions. When it is on, each new unsorted screenshot that GrabStack finds is sent in the same way as above, so the suggestion is ready when you open your Inbox. Screenshots you have already sorted are not sent. Switching off automatic suggestions, or stack suggestions, stops this straight away.

Where it goes

This information travels over an encrypted connection (HTTPS) to our server, which runs on Cloudflare. Our server passes the images and stack names to Anthropic's Claude API and sends the answer back to your phone. Our server does not save the images or the stack names. Claude returns a suggested stack, a short title and a few keywords for each screenshot, and these are saved on your phone.

What Anthropic does with it

Anthropic PBC processes this data for us as a service provider under its commercial terms. According to Anthropic's published policies as of the date of this policy:

• Anthropic does not use inputs and outputs from its API to train its models by default, and we have not opted in to any such use.
• Anthropic automatically deletes API inputs and outputs from its systems within 30 days of receiving or generating them.
• Anthropic may keep them for longer where it needs to enforce its Usage Policy (if a request is flagged, inputs and outputs may be kept for up to 2 years) or where the law requires it.

You can read Anthropic's policies at How long do you store my organization's data? and Anthropic's privacy policy.

Please choose with care

Screenshots can contain personal details about you or other people, such as messages, addresses or account numbers. Only pick screenshots you are comfortable sending, and avoid sending screenshots of identity documents, bank details or health information.

Allowance

The free version includes a monthly number of screenshots that can be sorted this way, and Pro includes a larger fair-use allowance. Only screenshots that were analysed successfully count towards it.

5. What our server keeps

The first time you open GrabStack, the app creates a random install ID on your phone. It is not based on your name, email, phone number or any hardware or advertising identifier. It is sent with stack suggestion requests and used to check your Pro status. You can see it, and copy it, in GrabStack's Settings under About. If you use Delete all GrabStack data, the install ID is deleted from your phone too, and a new random one is created the next time the app needs one. Our server, which runs on Cloudflare, keeps only:

• the install ID;
• how many screenshots that install ID has had analysed this month, and whether it has Pro;
• short-lived counters that limit how many requests can be made per hour from one install ID and from one IP address, to stop abuse.

Like any web server, ours receives your IP address with each request. We use it only for the hourly abuse limit. Cloudflare also processes IP addresses and basic request details to deliver and protect traffic, as described in Cloudflare's privacy policy.

6. Purchases and Pro

GrabStack Pro is an optional subscription or one-off purchase. Payments are taken by Apple through the App Store or by Google through Google Play. We never see your card details, your name or your Apple or Google account email.

We use RevenueCat, Inc. to confirm purchases and to tell the app and our server whether you have Pro. The app sends RevenueCat your store receipt together with the random install ID and basic technical details such as the app version, platform and store country. RevenueCat keeps a purchase history for that install ID on our behalf and gives us summary reports, such as how many people have subscribed, which we use to run the business. See RevenueCat's privacy policy. Apple and Google handle your payment under their own privacy policies.

Your purchase belongs to your Apple or Google account, not to the install ID. If you delete all GrabStack data or move to a new phone, tap Restore purchases in Settings to turn Pro on again.

7. Reminders

If you set a reminder, for example on a Want list item, GrabStack schedules it on your phone as a local notification. Your phone asks for permission to show notifications first. Reminders are not sent to us or to anyone else.

8. What we never do

• We do not ask you to create an account or sign in.
• The app contains no advertising or tracking tools and no analytics of how you use it, and it does not use your phone's advertising identifier. The only diagnostic data that leaves your phone is the ML Kit information on Android described in section 3.
• We do not sell or rent your data, share it with data brokers or use it to show you advertising.
• We do not track you across other companies' apps or websites.

9. Who receives data

We may also disclose data if the law requires it. If GrabStack is ever sold or transferred to someone else, this policy would continue to apply to the data they receive.

10. Legal bases

• Consent for stack suggestions, and a separate consent for automatic suggestions if you switch them on. You can withdraw either at any time in Settings, which stops any further sending straight away.
• Contract for providing the app, its allowance and Pro when you subscribe.
• Legitimate interests for the hourly limits and security measures that keep the service working and stop it being misused.

11. Data outside the UK

Anthropic, Cloudflare and RevenueCat are based in the United States, and Cloudflare runs servers around the world. When data is processed outside the UK, we rely on the safeguards in each provider's data processing terms, such as the UK International Data Transfer Addendum to the EU standard contractual clauses or, where the provider is certified, the UK Extension to the EU-US Data Privacy Framework.

12. How long data is kept

• On your phone: until you use Delete all GrabStack data in Settings or delete the app.
• Screenshots sent for suggestions: not stored by our server. Anthropic deletes them within 30 days, except in the cases described in section 4.
• Hourly limit counters: deleted automatically after about an hour.
• Install ID and monthly count: kept until the end of the following month and then deleted, unless the install ID is used again.
• Purchase history at RevenueCat: kept while it is needed to manage your subscription and our records, or until you ask us to delete it.

13. Deleting your data

• To delete everything GrabStack keeps on your phone, use Delete all GrabStack data in GrabStack's Settings, or delete the app. This removes the database (your library list, stacks, Want list, the text read from your screenshots, the titles and keywords from suggestions, and your settings and consent choices), the app's cached copies (the smaller copies made for suggestions, thumbnails, and share copies and collages), any scheduled and delivered reminders, and the install ID. A new random install ID is created the next time the app needs one. It does not delete any screenshots from your phone's photo library.
• Deleting your GrabStack data does not remove Pro. Your purchase belongs to your Apple or Google account, so afterwards tap Restore purchases in Settings to turn Pro on again.
• To stop sending screenshots for suggestions, switch stack suggestions off in GrabStack's Settings. To stop only the automatic suggestions for new screenshots, switch automatic suggestions off.
• To ask us to delete the counters on our server or your purchase history at RevenueCat sooner, contact us and include your install ID. You can find it in GrabStack's Settings, under About, Install ID, and copy it from there. Because we do not know who you are, the install ID is how we find the right records. If you plan to delete all GrabStack data as well, copy the install ID first, because a new one is created afterwards.
• To cancel a subscription, use your App Store or Google Play subscription settings. Deleting the app does not cancel a subscription.

14. Children

GrabStack is not aimed at children under 13, and we do not knowingly process personal data from children under 13. If you think a child has used stack suggestions, contact us and we will delete what we hold.

15. Security

The app talks to our server only over encrypted connections. Our Anthropic key is kept on the server and is never included in the app. Our server builds every request to Anthropic itself, and it does not save the images it passes on. No system is perfectly secure, but keeping almost everything on your phone means there is very little for anyone to take from us.

16. Your rights

Under UK data protection law you have the right to ask for a copy of your personal data, to have it corrected or deleted, to restrict or object to how we use it, to receive it in a portable format, and to withdraw consent at any time. Most of your GrabStack data is on your phone, where you can see, change and delete it yourself. For anything we hold, contact us and we will reply within one month.

If you are unhappy with how we handle your data, please contact us first so we can try to put it right. You also have the right to complain to the Information Commissioner's Office (ICO) at ico.org.uk/make-a-complaint or on 0303 123 1113.

17. This website and test feedback

This website does not use cookies, analytics or advertising, and it loads no third-party scripts or fonts. It is hosted on Cloudflare Pages, which processes your IP address to deliver the pages.

If you fill in the feedback form on our testing page, we store your answers, the device description shown on the form and your name if you give one. We use them only to improve GrabStack and delete them within 12 months. To stop spam, we keep a scrambled code made from your IP address for 24 hours. The web demo uses made-up screenshots and does not read anything on your device.

18. Changes to this policy

If we change this policy, we will update the effective date at the top. If a change affects how your screenshots are handled, we will tell you in the app before it applies, and we will ask for your consent again where the law requires it.

19. Contact us

For questions about privacy or to use any of your rights, contact us: