Privacy Policy¶
Effective date: October 8, 2026
This policy explains what personal data Experimenters processes when you visit experimenters.app, use the lab at circuits.experimenters.app or in the Experimenters Circuits app for Android, iPhone, iPad and Mac, or sign in to an account, why, for how long, and who else receives it. "The lab" here means both the lab in the browser and the app.
Who is responsible¶
Experimenters is run by Viktor Grigorev, a self-employed developer (autónomo) in Spain. He is the controller of the personal data described here. In this policy, "we", "us" and "our" mean Viktor Grigorev.
| Name | Viktor Grigorev |
| NIE | Z2528604N |
| Address | Puerta del Valle, Panorama Park 2, 03792 Murla (Alicante), Spain |
| info@experimenters.app, viktorgrigorevdev@gmail.com |
In short¶
- The lab works without an account. Your circuits stay on your device: you open and save them as files, and we do not receive them.
- An account needs only an email address. There are no passwords: you sign in with a code we email you, or through Apple or Google.
- Usage statistics in the lab and Google Analytics on the site run only if you allow them, and you can change your mind at any time.
- Error reports help us fix the lab and identify no one.
- We do not sell personal data and do not show advertising.
The lab¶
Using the lab without an account¶
The lab keeps your settings, such as the language, sound and your answer about usage statistics, on your device, and we do not receive them. The browser also keeps a copy of the lab's files so that it starts faster. You remove all of this by clearing the site data of circuits.experimenters.app in your browser, or by deleting the app. Circuit files you open or save go between the lab and your device only.
The same lab appears inside the Labs pages of experimenters.app, and this section applies there too.
Account¶
To create an account or sign in, you enter your email address and the code we send to it, or continue with Apple or Google; creating an account also requires accepting the Terms.
We store your email address, when the account was created, which edition of the Terms you accepted, and for each signed-in browser or app a session with the IP address and the browser or device description at sign-in. Sign-in codes are kept only in hashed form and only for a few minutes. If you sign in with Apple or Google, we also keep the identifier of that account and the tokens it issues, so that the link keeps working and so that we can withdraw the lab's access to your Apple account when you delete your account.
We use this data to provide the account (Article 6(1)(b) GDPR — performance of the contract) and to protect it against misuse, such as attempts to guess codes (Article 6(1)(f) GDPR — our legitimate interest in keeping accounts secure).
We ask Apple and Google only for your email address, not for your name or picture. You sign in on their own pages, under their own privacy policies (Apple, Google). If you use Apple's option to hide your address, our emails reach you through Apple. You can unlink Apple or Google on the account page; we then delete what we kept from it.
The only email we send is the sign-in code. We do not send newsletters or advertising.
Signing in in a browser sets cookies on circuits.experimenters.app that keep you signed in and protect the sign-in. They are strictly necessary for the account and are not used for anything else. Without "Remember me", the session ends when you close the browser; with it, it lasts up to 30 days after you last used the lab signed in. The app keeps its session on your device and removes it when you sign out.
Usage statistics (Unity Analytics)¶
Until you answer, the lab asks whether it may send usage statistics. If you allow it, the lab sends them to Unity Analytics, a service of Unity Technologies that processes the data on our behalf. The statistics show us which devices run the lab and how long it stays open, which helps us decide what to fix first. They include a random identifier of this installation of the lab, your IP address, the device, its operating system and settings, and the version of the lab.
- Legal basis: your consent (Article 6(1)(a) GDPR; Article 22.2 of the Spanish Law 34/2002, LSSI).
- Changing your mind: Settings → Usage statistics. When you switch statistics off, the lab stops sending them and asks Unity to delete what it collected from this installation.
- Retention: up to 13 months.
- Transfers: Unity may process the data outside the European Union, including in the United States, under Unity's Data Processing Addendum.
If you are under 14, ask a parent, guardian or teacher before allowing statistics.
Error reports (Sentry)¶
When the lab, its page or the sign-in service runs into an error, or the app crashes, a technical report goes to Sentry, a service of Functional Software, Inc. that processes it on our behalf in its EU data region in Germany. The report describes the error, the device and the version of the lab. It is set up to identify no one: it contains no account data, and Sentry does not keep IP addresses or device identifiers from it. Reports are deleted after at most 90 days.
We rely on our legitimate interest in finding and fixing errors (Article 6(1)(f) GDPR). You can object by writing to us.
The App Store¶
Apple distributes the app through the App Store under its own privacy policy. If you allow your iPhone, iPad or Mac to share analytics with app developers, Apple passes us crash reports and usage figures of the app that do not identify you.
Google Play¶
Google distributes the Android app through Google Play under its own privacy policy. If you allow your Android device to share usage and diagnostics with developers, Google passes us crash and performance figures of the app that do not identify you.
The website¶
Server logs¶
Our web server logs each request to experimenters.app, circuits.experimenters.app and the sign-in service: the IP address, time, address requested and browser description. We use the logs to keep the sites running and secure and to count visits to the lab by day; the daily counts contain no IP address (Article 6(1)(f) GDPR). The logs are deleted after seven days.
Google Analytics¶
With your consent, experimenters.app uses Google Analytics, a service of Google Ireland Limited, to count visits: which pages are read, and from which sites and countries visitors come. Until you accept in the cookie dialog, Google Analytics does not load.
- What Google receives: the pages you visit, the referring site, your browser and device, and your IP address,
from which Google derives an approximate location. Google sets its cookies (
_ga,_ga_13KTRYDV8T) for up to two years. - Legal basis: your consent (Article 6(1)(a) GDPR; Article 22.2 LSSI).
- Changing your mind: "Cookie settings" at the bottom of every page.
- Retention: up to 14 months.
- Transfers: Google may process the data in the United States under the EU–U.S. Data Privacy Framework.
The site keeps your cookie choice and your light or dark theme in your browser.
Formulas¶
Pages with formulas load the MathJax library from jsDelivr, a public content delivery network, which receives your IP address in order to deliver the file (Article 6(1)(f) GDPR — our interest in displaying the formulas). Fonts and images come from our own server.
Contacting us¶
If you write to us by email or through the feedback form (Google Forms), we use what you send to answer you and keep it as long as the matter needs it (Article 6(1)(f) GDPR). Links to X, LinkedIn and Product Hunt are plain links; those sites receive nothing from us.
Who receives data¶
| Recipient | What for | Where |
|---|---|---|
| Hostinger International Ltd. | the server that runs the sites, the lab, the sign-in service and the mail server | the Netherlands |
| Functional Software, Inc. (Sentry) | error reports | EU data region, Germany |
| Unity Technologies | usage statistics, only with your consent | may include the United States |
| Apple Distribution International Ltd., Apple Inc. | the App Store; Sign in with Apple, if you choose it | may include the United States |
| Google Ireland Limited, Google LLC | Google Play; Sign in with Google, if you choose it; Google Analytics, only with your consent; the feedback form and our mailbox | may include the United States |
| jsDelivr | delivering MathJax on pages with formulas | worldwide network |
We disclose personal data to authorities only when the law requires it.
How long we keep data¶
| Data | Kept |
|---|---|
| Account and Apple or Google sign-in | until you delete the account or unlink the sign-in |
| Sessions | until you sign out or the session expires |
| Sign-in codes | a few minutes |
| Records of sign-in attempts, kept against misuse | up to two days |
| Server backups | 30 days |
| Web server logs | seven days |
| Usage statistics (Unity) | up to 13 months, or until you switch statistics off |
| Error reports (Sentry) | up to 90 days |
| Google Analytics | up to 14 months |
| Correspondence | as long as the matter needs it |
When you delete your account, we delete the account, its sessions and its Apple and Google sign-ins at once, and ask Apple to withdraw the lab's access to your Apple account. Copies in backups are overwritten within 30 days.
Your rights¶
You have the right to access your personal data, to have it corrected or deleted, to restrict or object to its processing, and to receive the data you gave us in a portable form. Where we rely on your consent, you can withdraw it at any time; this does not affect processing that took place before.
- Delete your account yourself: in the lab, open the account page and follow the link to delete the account.
- Everything else: write to info@experimenters.app. We answer within one month.
You also have the right to lodge a complaint with the Spanish Data Protection Agency (Agencia Española de Protección de Datos, aepd.es) or with the supervisory authority of the EU country where you live.
Children¶
The lab works without an account for everyone. You can create an account from the age of 14. For a child under 14, a parent or guardian creates the account and agrees to the Terms. If we learn that a child under 14 created an account without that, we delete the account.
Security¶
The sites work only over HTTPS, and sign-in codes are stored only in hashed form. We make no decisions about you by automated means.
Changes to this policy¶
When this policy changes, we publish the new version on this page with a new effective date. If a change affects how we use the data of account holders, we tell them by email before it takes effect.
Contact¶
Questions about this policy and about your data: info@experimenters.app.