Privacy Policy
Physics Sandbox is a small physics-learning toy that runs entirely in your browser. This page explains, in plain English, what data the app handles and where it goes.
What we collect
Nothing personally identifying. No accounts, no email, no name, no IP-address logging by us, no tracking pixels, no analytics scripts.
What is stored on your device
The app uses your browser's localStorage to remember a few preferences. These never leave your device and we cannot read them remotely. The full list:
physicsMode— your 2D or 3D mode preference.ps.pro— local Pro flag. Honest disclosure: this is a local flag in your browser; it's the same kind of toggle a settings page uses. Anyone with developer tools can change it on their own device. Pro is sold on the honor system — if you genuinely paid via Stripe, the flag stays set; if you set it yourself, that's between you and your conscience.ps.hintDismissed— whether you've dismissed the onboarding hint.ps.educator.level— your selected educator level (Curious / Beginner / Intermediate / Expert).ps:layout:*— panel widths, heights, dock state, floating rects, collapsed/hidden flags.- (Pro) Locally saved scenes you choose to download as
.json.
You can clear all of this at any time via your browser's "Clear site data" tools, or by visiting Settings → Privacy in your browser.
Payments
If you upgrade to Pro, payment is handled by Stripe. We do not see, store, or process your card. Stripe's privacy policy applies to the checkout flow: stripe.com/privacy.
After a successful purchase, Stripe redirects you back to physics.stacklis.com/app/ with a flag in the URL that activates Pro on your device. We do not retain a customer record beyond what Stripe keeps for tax and refund purposes.
Telemetry & analytics
None. By design. This app ships with no analytics, no error reporting service, and no third-party tracking. If we ever add any, this page will be updated and the change will be announced in-app before it takes effect.
Cookies
The app itself does not set cookies. Stripe's checkout page (on Stripe's domain, not ours) may set cookies it needs to process your payment — those are governed by Stripe's policy.
Children
Physics Sandbox is suitable for all ages and does not collect personal data from anyone, including children under 13.
Refunds
If Pro doesn't work for you, email support@stacklis.com within 14 days of purchase for a full refund. Include your Stripe receipt for fastest turnaround.
Open source
The client-side code is open and inspectable — you can verify the no-telemetry claim by reading the source on the GitHub repository linked from the landing page.
Contact
Questions or requests: support@stacklis.com.
Changes to this policy
We'll update the "Effective" date at the top of this page if anything changes. For substantive changes (e.g., adding analytics), the change will be highlighted in-app the next time you load the sandbox.