Stack
Privacy Policy
Effective: 07/31/2026 · Last updated: 10/12/2026
The short version: Stack stores everything you enter only on your own device. We do not collect it, we cannot see it, it is never uploaded to a server we control, and it is never sold or shared. There are no user accounts, no analytics, and no advertising in this app.
1. Who this policy is from
Stack ("the app") is developed and published by Uptick Studio ("we", "us", "our"). This policy explains how the app handles information when you use it.
If you have questions about this policy or about privacy in the app, contact us at: uptickstudio459@gmail.com
2. What Stack is
Stack is a personal logging tool. It lets you record what supplements, peptides, or medications you take and when, track injection sites and supply levels, keep a record of the batches you buy, record values from lab work you already have, and view your own history over time.
Stack is a record-keeping tool only. It does not provide medical advice, diagnosis, treatment recommendations, or dosing recommendations. See section 12.
3. Information you enter into the app
Depending on how you use Stack, you may choose to enter information such as:
- Names of supplements, peptides, or medications you are tracking, and the amounts and schedules you set
- Records of when you logged a dose, including date and time
- Injection site selections and optional notes about how a site felt
- Supply and inventory amounts (for example, how much is left in a vial or kit)
- Lab or bloodwork values you choose to type in, with their dates
- Batch records for what you buy: the code you scanned, when you bought it, the vendor, how you paid, a transaction ID or sales rep if you add one, and any test results you type in
- A photo you attach to a batch record, such as a photo of its test results
- Any free-text notes you add
Where this information is kept: all of it is saved using your browser or device's local storage on the device where you use Stack. It stays on that device. It is not transmitted to us, and we have no server, database, or account system that receives or holds it. We cannot read it, retrieve it, or recover it for you.
Sensitive information
We recognize that information about substances you take and lab values may be health-related and personal to you. Because this information never leaves your device and is never sent to us, we do not collect, process, store, transmit, sell, or share it. The privacy protection here comes from the app's design: there is nowhere for that data to go.
4. Information the app does not collect
To be explicit, Stack does not:
- Require or offer an account, login, email address, or password
- Include analytics, usage tracking, behavioral profiling, or crash-reporting SDKs
- Include advertising or advertising identifiers
- Request access to your contacts, microphone, calendar, or precise location
- Track you across other apps or websites
- Sell or rent any information to anyone, or share information with data brokers
Camera, photos, and files
Stack turns on your camera only while the scanner is open, to read a code on a package or label. Your device asks for your permission first. The camera image is read on your device and is not saved, uploaded, or sent anywhere. Closing the scanner turns the camera off. You can withdraw camera permission at any time in your device or browser settings.
When you add a photo to a batch record, you pick or take it through your device's own photo picker. Stack keeps a compressed copy of that one photo with the record, on your device. It does not read the rest of your photos or files. Importing a backup reads only the backup file you choose.
5. Third parties involved in delivering the app
Although your logged data stays on your device, loading and installing any app involves some third-party infrastructure. For full transparency, here is every third party involved and what they may see:
| Third party | Why it is involved | What it may receive |
|---|---|---|
| Vercel (hosting provider) | Hosts the app's files so your device can load them, and runs the check that confirms a purchase with Google Play | Standard web server information when the app loads or a purchase is checked, such as IP address, timestamp, and device/browser type. This is normal server logging and is not linked to anything you log in the app. |
| Google Fonts | Supplies the typefaces the app's design uses | Your IP address, as part of the request for the font files. No app content or logged data is included in that request. |
| Google Play | Distributes and updates the app if you installed it from the Play Store | Install, update, and (if applicable) purchase information, handled under Google's own privacy policy, not ours. |
None of these parties receive the health-related information you enter into Stack, because that information is never sent anywhere.
Buying Stack
If you buy Stack, Google Play takes the payment under Google's own privacy policy. We never see your card or your Google account details.
To finish the purchase, Stack sends Google Play's purchase token to a small function on our hosting. The token is a code that identifies the purchase. It says nothing about you or anything you log. The function asks Google whether the purchase is complete and confirms it, which Google requires within three days. Then it forgets the token. It stores nothing, and its logs record only whether the check worked. If the connection drops, Stack tries again at the next launch.
Your device keeps the purchase, and the date a free trial started, with the rest of Stack's data. A reinstall or a new phone on the same Google account gets the purchase back from Google Play, not from us.
6. Backups and files you create yourself
Stack includes an export feature that lets you save a backup file of your own data, and an import feature that lets you restore one. When you export a backup:
- The file is created on your device and saved wherever you choose to save it
- It is not uploaded to us or to any third party by the app
- Once you have that file, you control it — including if you move it to cloud storage, email it, or share it with someone. Anything that happens to it after export is governed by whatever service you put it in, not by this policy.
The same applies to everything else Stack makes at your request: a CSV of your dose history, an image of a code you save or print, and a summary of lab results you copy.
Because backup files contain your logged information in readable form, we recommend storing them somewhere you consider private.
7. How long information is kept, and how to delete it
Because we never receive your information, we do not retain it and there is nothing for us to delete on your behalf. You are in full control:
- You can delete individual log entries, compounds, lab results, batch records, or batch photos inside the app at any time
- Clearing the app's or browser's storage for Stack removes all of its stored data on that device
- Uninstalling the app removes its locally stored data from that device
- Any backup files you exported yourself remain wherever you saved them until you delete them
If you bought Stack, our server checked the purchase with Google and kept nothing (see section 5), so there is nothing of yours to delete there either. Google Play keeps the purchase on your Google account, under Google's own privacy policy. To ask us about your data, write to the address in section 14.
Important
Because your data lives only on your device and we hold no copy, deleting the app, clearing its storage, losing the device, or resetting the device will permanently erase your history. We cannot restore it. If your records matter to you, export a backup regularly.
8. Security
Stack is served over an encrypted HTTPS connection. Because your information stays on your own device and is not transmitted to or stored by us, the largest factor in keeping it private is the security of the device itself. We recommend using your device's screen lock, keeping your operating system updated, and being thoughtful about where you store exported backup files.
No method of electronic storage is completely secure. While the app's local-only design substantially limits exposure, we cannot guarantee absolute security of information held on your device.
9. Children's privacy
Stack is not directed to children and is not intended for use by anyone under 18. We do not knowingly collect information from children — and, as described above, we do not collect information from any user. If you believe a child has been using the app, clearing the app's storage or uninstalling it will remove the locally stored data.
10. Your privacy rights
Privacy laws in various regions — including the EU and UK General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA/CPRA) — give people rights over personal information that a company holds about them, such as the right to access, correct, delete, or port that information, and the right to opt out of its sale.
Because we do not collect, receive, store, sell, or share your information, there is no personal information held by us for these requests to apply to. You already have direct and complete access to all of your data through the app itself, and can edit, export, or delete it at any time without asking us.
We do not sell personal information, and we do not share it for cross-context behavioral advertising.
If you have a privacy question or want to raise a concern, contact us at uptickstudio459@gmail.com and we will respond.
11. International use
Stack can be used anywhere the Play Store is available. Because your logged information remains on your own device, using the app does not involve us transferring that information across borders. Requests to the hosting and font providers described in section 5 may be served from infrastructure located in other countries.
12. Not medical advice
Health disclaimer
Stack is a personal record-keeping and organization tool. It does not provide medical advice, diagnosis, or treatment, and it does not recommend any substance, dose, schedule, or course of action. Any calculators in the app perform arithmetic on values that you enter; their output is not a recommendation and does not verify that what you entered is appropriate or safe.
Reference information in the app is general educational material and is not tailored to you. Many substances people track are experimental, investigational, or available by prescription only, and their safety profiles vary. Always consult a qualified healthcare professional before starting, stopping, or changing anything you take, and never disregard professional medical advice because of something you saw in this app.
13. Changes to this policy
We may update this policy if the app changes or to reflect legal or operational requirements. When we do, we will revise the "Last updated" date at the top of this page. If a change materially affects how information is handled, we will make a reasonable effort to notify users through the app or its Play Store listing. Continuing to use Stack after an update means you accept the revised policy.
14. Contact
Questions, concerns, or requests about this policy can be sent to:
- Email: uptickstudio459@gmail.com
- Developer: Uptick Studio
- App: Stack