Legal
Privacy Policy
This policy describes what GAIT Analysis (StepDoctor) collects through the mobile app, the website and the current open-testing product, how that information is used, and who it is shared with.
Information we collect
We collect information you provide directly: your name, email address, account credentials, profile details, support messages, and content submitted through the signup or contact flows. If you sign in with Apple or Google, we receive the name and email address that provider shares with us. We also collect operational data needed to run the service, such as log, usage and purchase information.
Gait videos and analysis results
When you record or upload a walking, Timed Up and Go (TUG) or Short Physical Performance Battery (SPPB) video, it is analysed by our own models, on your device or on servers we operate, to produce gait scores and measurements such as walking speed, cadence, stride length, phase times and SPPB points. Videos are used only to produce your results and are automatically deleted from our servers after a short retention period. The resulting scores and measurements are stored with your account so you can follow your progress. This data is never sold or used for advertising.
AI chat (Ask AI)
The optional Ask AI feature answers questions about one of your reports. When you use it, the questions you type and that report's scores and measurements are sent to our servers and processed by a language model that we host and operate ourselves. Your name and email address are not included. This data is not sent to or shared with any third-party AI service or AI provider. The app asks for your permission before you send your first message. Chats are deleted automatically 30 days after they start, or sooner if you delete your account, and they are never used to train AI models.
Device identifier and diagnostics
The app sends a device identifier with its requests (Android ID on Android; a random identifier kept in the iOS keychain on iOS), which we store only in hashed form, so that each device receives the welcome credit bonus once and to prevent abuse. If the app crashes or hits an error, it sends crash and diagnostic information, such as the error, app version and device model, to an error-monitoring service that we host ourselves. Diagnostic data is linked only to your account ID, never to your name or email address.
Website analytics and session recordings
When you visit our website, we record how the site is used so we can find errors and improve it: the pages you view, clicks, scrolling, time on page, errors, browser and device type, and recordings of your session that replay these interactions. Everything you type into forms is masked in recordings and never captured, and in GAIT Studio we record only a fully masked minute around an error, never whole sessions. A first-party cookie (gait_vid, kept for one year) gives your browser a random identifier so we can count unique visitors. We estimate your country, region and city from your IP address on our own servers and keep only that location, never the IP address itself (IP geolocation by DB-IP, db-ip.com, licensed under CC BY 4.0). This data goes to the error-monitoring service we host ourselves, is linked only to the random identifier or your account ID, and is not used for advertising. If your browser sends a Global Privacy Control or Do Not Track signal, we record errors only: no session recordings or interaction data.
How we use information
We use information to provide the service: to create and secure your account, analyse your videos and show your results, answer your AI chat questions, process purchases and credits, send the notifications you enable, respond to support requests, keep the service reliable, and protect it from abuse. We do not sell personal information or use it for advertising.
Who we share information with
Video analysis, AI chat, data storage and error monitoring run on infrastructure we operate, and none of this data is shared with third-party AI services. We share limited data with the following providers only as needed for the features you use: Apple and Google, for sign-in with Apple or Google and for in-app purchases; Google Firebase, for sign-in and push notifications (a device push token); Stripe, for web payments; and our email delivery provider, for account emails. Each provider receives only the data needed for that purpose and is required to protect it to a standard at least equal to this policy. We may also disclose information when required by law, to enforce our terms, or to protect users and the service.
Retention and deletion
We keep account data and analysis results while your account is active. AI chats are deleted automatically 30 days after they start. Videos are automatically deleted from our servers after a short retention period. When your account is deleted, its analysis results, chats and related data are deleted with it. For account deletion instructions, see the data deletion page.
Security and updates
We use administrative, technical, and organizational safeguards appropriate for an open-testing product, including encrypted connections and access controls, but no system can promise absolute security. We will update this policy when the product, the data it uses or the providers we rely on change.