App Stack

Privacy

Last updated 27 October 2026

1. Who is responsible

The controller of your personal data is Martin Jiřička, [address], Czech Republic, Company ID (IČO) [IČO]. For anything about your data, write to hello@appstackmac.com.

2. What we process and why

The App Stack app

The app works on your Mac. Your stacks, the apps in them and your settings are stored only on your Mac, in your user account. We don't receive them.

The app makes two kinds of connections: the update check described below, and, with a license, license requests. It contacts the Lemon Squeezy license server (api.lemonsqueezy.com) only:

• when you activate a license;
• when the app starts, if a license is active and at least 30 days have passed since the last successful check, to check it is still valid;
• when you deactivate a Mac.

It sends the license key, the activation ID for your Mac, and on activation a label for your Mac: its model (for example “Mac14,7”) and a short code calculated from your Mac's hardware ID, so that we and you can tell your two Macs apart. The label contains neither your name, your computer's name nor the hardware ID itself, and the code can't be turned back into it; but because it is sent with your license key, it is linked to your purchase, so we treat it as personal data. As with any connection, the server also sees your IP address. The license server answers with whether the key is valid and with the name and email address of the purchase; the app keeps them on your Mac and shows them in its About and license windows.

Why: to provide the license you bought (performance of a contract, Art. 6(1)(b) GDPR) and to prevent the key from being used beyond its terms (our legitimate interest, Art. 6(1)(f) GDPR).

Software updates

While the main App Stack app is running, it checks appstackmac.com for updates automatically, normally once a day, including on first launch. You can turn automatic checks off in About App Stack; manual checks remain available. The app may download release notes when an update is found. Update files are downloaded only when you choose to install an update. These connections expose your IP address, the requested resource and standard request metadata to Cloudflare, our hosting provider. App Stack's update requests include a User-Agent identifying App Stack's version and the Sparkle updater version. We do not add a device identifier or send your stack contents or a system profile. We do not use update requests for analytics or advertising. You can continue using your stacks with automatic checks off.

Why: our legitimate interest in delivering fixes, including security fixes, to the copies people have installed, and in letting them know a new version exists (Art. 6(1)(f) GDPR). We weighed this against your interests: the check sends what any web request sends and nothing more, you are told about it in the app before the first check, and you can turn it off. You can object at any time (section 8).

Buying a license

The license is sold by Lemon Squeezy (Link, LLC, formerly Lemon Squeezy LLC), our reseller and merchant of record. Lemon Squeezy collects your payment and billing details at checkout and is responsible for them under its own privacy policy. We never see your card details.

Lemon Squeezy shares with us what we need to give you the license and support it: your name, email address, country, order details (number, date, amount), your license key and its activations (the Mac labels described above). We use this to deliver and support your license, handle refunds, and meet our tax and accounting obligations.

Why: performance of a contract (Art. 6(1)(b)), legal obligations (Art. 6(1)(c)) and our legitimate interest in handling support and preventing misuse (Art. 6(1)(f)).

Email

If you write to us, we receive your email address and whatever you write, and use it to answer you. Why: our legitimate interest in answering you, or steps towards or under a contract (Art. 6(1)(f) and (b)).

This website

appstackmac.com is a static website hosted by Cloudflare. To deliver the pages and protect the site from attacks, Cloudflare processes technical data such as your IP address, browser type and the pages requested. We don't run analytics, and the site loads no fonts, scripts or images from other companies. Why: our legitimate interest in running a working, secure website (Art. 6(1)(f)).

3. Cookies

This website doesn't set cookies and doesn't store anything in your browser. Cloudflare may set a strictly necessary security cookie if it needs to check that a visitor isn't a bot; such cookies need no consent. The checkout runs on Lemon Squeezy's website, which uses its own cookies under its own policy. The app uses no cookies.

4. Who receives data

Some of these companies are in the USA. For Cloudflare, which processes data for us, the transfer relies on its certification under the EU–US Data Privacy Framework and the European Commission's standard contractual clauses in its data processing agreement. Lemon Squeezy is responsible for its own transfers as an independent controller; see its privacy policy. You can ask us for a copy of the safeguards we rely on. We don't sell personal data and don't share it with anyone else, unless the law requires us to.

5. How long we keep it

• Purchase records: for as long as your license exists, and then as long as tax and accounting law requires (in the Czech Republic up to 10 years).
• License activations: until you deactivate the Mac or the license ends.
• Emails: as long as needed to help you, and no longer than 3 years after our last message, unless we need them for a legal claim.
• Website and update logs: we don't keep or see visitor logs, and we don't keep or see logs of the app's update checks and downloads. Cloudflare processes the request data to deliver and protect the site and keeps it as described in its privacy policy.
• On your Mac: the license key, the purchase name and email, and the activation ID stay in your Mac's preferences until you deactivate the license (About App Stack › Deactivate This Mac). Your stacks and their settings stay until you delete them. Deleting the app alone doesn't remove its preferences; see “Removing App Stack completely” below.

6. Removing App Stack completely

1. If you have a license, open About App Stack and choose Deactivate This Mac. This frees the activation at Lemon Squeezy and removes the license from your Mac.
2. Open Manage Stacks… and delete every stack. This also deletes each stack's settings.
3. Move App Stack to the Trash.
4. To remove the last settings, delete the files starting with com.mjiricka.appstack in the Library › Preferences folder of your user account.

7. Do you have to give us data?

No. You can use the free version with automatic update checks turned off. Update checks and downloads require a connection to our hosting provider. Purchasing and activating a license requires the information described above: the order details and the license key are needed to provide it (it's part of the contract). Without them you can't use the licensed features, but the free version keeps working.

8. Your rights

You have the right to access your data, to have it corrected or deleted, to restrict its processing, to data portability, and to object to processing based on our legitimate interest. Write to hello@appstackmac.com; we'll reply within a month. We may need to keep some data to meet legal obligations, for example invoices.

If you object to the update check, we'll confirm it and tell you how to turn automatic checks off in About App Stack, which stops future scheduled checks; a manual check happens only when you ask for it. The license requests described above are separate and are not affected by that switch. We keep no logs of update requests ourselves; for request data held by Cloudflare we'll ask it to delete or restrict what can be attributed to you and tell you what it could do. If we can't act on a request, we'll tell you why, and you can complain to the authority named below.

You can also complain to a data protection authority: in the Czech Republic, the Office for Personal Data Protection (ÚOOÚ), or the authority where you live or work.

9. Other things you should know

• We make no automated decisions about you and don't profile you.
• App Stack isn't meant for children under 16, and we don't knowingly collect their data.
• If we change how we handle data, we'll update this page and its date first.