Your training data stays on your device

Everything you log in Stone – workouts, sets, reps, weights, personal records, bodyweight entries, notes, programs, and your full history – is stored in a private database on your iPhone.

There is no account, no login, and no cloud sync. Stone has no server that stores your training history, so your data is not sitting in someone else's database. It stays with you unless you choose to export it.

Anonymous, privacy-friendly analytics

To understand which features matter and where people get stuck, Stone uses PostHog for anonymous product analytics. We look at trends in aggregate – never the contents of your training.

What we measure

A random, anonymous identifier created for each install. It is not linked to your name or identity.
Which features and screens you use, and how far you get through onboarding and import.
Your app version and basic device type.
Coarse preferences like theme, accent color, units (lb/kg), and equipment setup.
Aggregate training stats – such as total workout count, rounded lifetime volume, and PR counts – used only for anonymous community benchmarks.

What we never collect

Your name, email, Apple ID, or any account identifier.
Your workout notes or the contents of files you import.
Your specific bodyweight values – we only note whether you have set one.
Any Apple Health data.

Analytics are processed by PostHog and stored on US-based infrastructure. We do not run session replay, we do not capture your screens, we do not use advertising networks, and we never sell your data.

Crash reports & diagnostics

So we can find and fix bugs, Stone sends an automatic report when the app crashes or hits a serious error. These reports are handled by Sentry, a crash-reporting service, on US-based infrastructure.

What a crash report includes

What went wrong – the technical error and where it happened in the code.
Your device model, iOS version, and the Stone version and build you are running.
A short trail of recent in-app actions (for example, "opened History") to help us reproduce the problem.

What a crash report never includes

Your name, email, or Apple ID – crash reports are not tied to your identity.
Screenshots or a copy of what is on your screen – we have these turned off.
Your workouts, notes, bodyweight values, or any Apple Health data.

We use crashes only to keep Stone stable. We do not use Sentry for analytics, performance tracking, or session replay.

Feedback you send us

Stone has an optional Send Feedback form in Settings. If you use it, we receive only what you choose to send so we can read it and follow up. Nothing leaves your phone unless you tap Send.

What you send when you submit feedback

Your message – the summary and details you write.
Your email, only if you add it so we can reply. You can leave it blank.
Basic diagnostics to help us reproduce issues: the Stone version and build, your iOS version, device model, and language/region, plus your anonymous analytics identifier – never your name.

Feedback is delivered through a small server we run and stored as a private issue in our source-code repository on GitHub. If you report a bug, the same message (and your email, if you added one) is also sent to Sentry so we get the device context to fix it.

Your feedback text and email are never sent to our analytics. PostHog only records that feedback was submitted and its category (bug, idea, or other) – never what you wrote.

Price

Stone is free to download and fully free to use. There is no trial, in-app purchase, subscription, or ads, so we never collect payment details.

This website

stoneworkout.com uses Google Analytics to understand how people find and use this marketing site. Google may set cookies or similar technologies in your browser and collect information such as pages viewed, approximate location, device type, and referral source.

This is separate from analytics inside the Stone iPhone app (described above). We use site traffic only to improve the website – not to track your workouts or sell data.

Your data, your control

Export anytime. From inside the app you can export your full history to CSV or JSON. Viewing and exporting your own data is free, forever.
Delete anytime. Deleting Stone removes its on-device database. You can also reset your data from within the app.
Analytics. Because analytics are anonymous and not linked to you, we cannot single you out.
Feedback. Adding your email to feedback is optional and only used to reply. Ask us through the feedback form and we will remove it.

Children

Stone is not directed at children under 13, and we do not knowingly collect personal information from children.

Changes to this policy

If this policy changes, we will update the date at the top of the page and, for anything significant, call it out in the app's What's New.

Contact

Questions about privacy? Send feedback – add your email if you'd like a reply.

Privacy Policy