Privacy Policy
How Moon Shard Ltd handles information when you use TennisLens.
Last updated 1 June 2026
1. Who we are
TennisLens is a product operated by Moon Shard Ltd("Moon Shard", "we", "us", or "our"). This policy covers the TennisLens mobile application and website, together called the "Service". Moon Shard Ltd is the data controller responsible for your personal information under the UK General Data Protection Regulation ("UK GDPR") and the Data Protection Act 2018.
If you have any questions about this policy or how we handle your information, you can reach us at tennislens@moonshard.co.
2. Scope of this policy
This policy covers the TennisLens app (iOS and Android) and the TennisLens website. It does not cover third-party services that have their own privacy policies, such as the Apple App Store, Google Play, or TikTok, even where you reach them through the Service. We encourage you to read the privacy policies of those third parties.
3. Information we collect
TennisLens is designed to collect as little as possible. We do not require you to create an account, and we do not ask for your name, email address, or password to use the core features. The information involved in the Service falls into the following categories:
a. Clips you submit for analysis
When you choose to analyse a stroke, the video clip you record or upload, including any audio it contains, is transmitted to our processing backend and on to our AI provider for analysis. These clips may show you or other people. We use them only to generate your technique analysis and we do not store them after the analysis is complete (see sections 6 and 9).
b. Optional notes
The analysis flow includes an optional free-text field where you can add context (for example, "my second serve has no kick"). If you provide notes, they are sent to our AI provider together with the clip to inform the analysis. We recommend you do not include sensitive personal information in this field. Notes are not stored on our servers after the analysis is complete.
c. Technical and usage information
- IP address. When your device contacts our backend, your IP address is processed to deliver the response and to operate our rate limiting (to prevent abuse and manage capacity). It is held only transiently for these purposes.
- Device identifier.The app generates a random identifier on your device (a UUID) that is sent with analysis requests purely to count usage for rate limiting. It is not your Apple/Google advertising identifier, it is not linked to your identity, and it is not used for advertising or cross-app tracking. It is removed if you uninstall the app or clear the app's data.
- Limited request metadata. Our backend may log standard technical information (such as timestamps, request status, and a client/version header) for security, debugging, and reliability.
d. Information stored only on your device
Your analysis history (scores, the shot type you selected, your skill tier, clip duration, and timestamps) and your onboarding answers (such as self-reported skill level, the shot you want to focus on, court surface preference, how often you play, and where you heard about the app) are saved locally on your device only. This information is not transmitted to us. See section 8.
e. Subscription information
If you purchase a subscription, the transaction is handled by the Apple App Store or Google Play. We receive confirmation of your subscription status from those stores but we do not receive or store your full payment card details. See section 12.
4. What we do not collect
To be clear about the things we deliberately avoid:
- We do not require or collect names, email addresses, or passwords for the core Service.
- We do not use third-party analytics, advertising, or marketing-tracking SDKs in the app.
- We do not use facial recognition or any biometric identification on your clips. We analyse stroke mechanics, not identity.
- We do not sell or rent your personal information to anyone.
- We do not build advertising profiles or track you across other apps and websites.
- We do not "track" you as defined by Apple's App Tracking Transparency framework, and we do not access your device's advertising identifier (IDFA). We therefore do not present the App Tracking Transparency prompt because we have nothing to track.
- We do not retain your videos or notes after your analysis is generated.
5. How we use your information and our legal bases
Under the UK GDPR we must have a lawful basis for processing personal information. The table below sets out what we do and why.
| Purpose | Information used | Lawful basis |
|---|---|---|
| Generate your stroke analysis | Your clip, audio, and optional notes | Performance of a contract / taking steps at your request; and your action of submitting the clip |
| Prevent abuse, rate-limit usage, keep the Service secure and reliable | IP address, device identifier, request metadata | Legitimate interests (protecting and operating the Service) |
| Provide and manage subscriptions | Subscription status from the app stores | Performance of a contract |
| Respond to your enquiries and exercise of rights | The contact details and information you provide | Legitimate interests; legal obligation |
| Comply with legal and regulatory obligations | As required | Legal obligation |
6. AI processing of your clips
The technique analysis is produced by a third-party large language / multimodal AI model provided by Google (the Gemini family of models). When you analyse a clip:
- Your clip (video and audio) and any optional notes are sent to the AI provider together with our coaching instructions.
- The provider processes the clip to generate the analysis and returns structured results to you.
- The clip is sent as part of the request and is not stored by us afterwards. The AI provider processes the content to provide the response and in accordance with its applicable enterprise/API data-handling terms.
We do not send your device identifier, IP address, or on-device history to the AI provider as part of the analysis content. You can review Google's relevant terms and privacy information on its website.
7. Video and audio
To analyse your technique the app needs access to your camera (to record) and/or your photo library (to choose an existing clip), and it captures the audio recorded with your video. iOS and Android will ask for your permission before granting access, and you can change these permissions at any time in your device settings. The relevant permission prompts in the app are:
- Camera: so you can record clips of your strokes for analysis.
- Microphone: audio is recorded with your video clip and sent for analysis with the stroke.
- Photo library: so you can pick a previously recorded clip to analyse.
If you do not grant a permission, the related feature will not work, but you can still use the rest of the app.
8. Information stored on your device
Your analysis history, scores, and onboarding answers are stored locally on your device using your operating system's standard app storage. This information stays on your device and is not uploaded to us. It is protected by your device's own security. You can remove all of this information at any time by clearing the app's data or uninstalling the app, and by using any in-app reset option we provide.
9. Storage and retention
- Clips, audio, and notes: processed transiently to generate your analysis and not retained by us afterwards.
- Rate-limiting data (IP address and counts): held only for the duration of the rolling rate-limiting window (approximately one day) before it expires.
- Technical logs: kept only for as long as needed for security, debugging, and reliability, then deleted or aggregated.
- On-device data: retained on your device until you clear it or uninstall the app. It is under your control and is not stored by us.
- Subscription records: retained as required to administer your subscription and to meet legal, tax, and accounting obligations.
10. Who we share information with (sub-processors)
We do not sell your data. We use a small number of trusted service providers who process information on our behalf, under contract, to operate the Service:
| Provider | Purpose | Information involved |
|---|---|---|
| AI analysis of your clip (Gemini models) | Your clip, audio, and optional notes | |
| Cloudflare | Backend infrastructure that receives the app's analysis requests | Clip in transit, IP address, request metadata |
| Netlify | Hosting for the informational TennisLens website | Standard web server logs (e.g. IP address) |
| Upstash | Rate limiting and abuse prevention | IP address and request counts |
| Apple / Google (app stores) | App distribution and subscription billing | Subscription transaction handled by the store |
Each provider acts as our processor (or, for the app stores, an independent controller for payments) and is engaged under terms that require it to protect your information to a standard consistent with this policy and with applicable data protection law, and to use it only to provide its service to us. You can review each provider's own privacy practices here: Google, Cloudflare, Netlify, Upstash, Apple, Google Play, and (for embeds) TikTok.
We may also disclose information if required to do so by law, to enforce our terms, or to protect the rights, property, or safety of TennisLens, our users, or others. If our business is ever reorganised, merged, or sold, information may be transferred as part of that transaction, subject to this policy.
11. International data transfers
Some of our service providers are located outside the United Kingdom, including in the United States. Where personal information is transferred outside the UK, we rely on appropriate safeguards recognised under UK data protection law, such as the UK International Data Transfer Agreement or Addendum, the UK extension to the EU Standard Contractual Clauses, or a finding of adequacy, to ensure your information remains protected.
12. Subscriptions and payments
TennisLens may offer paid subscriptions, including auto-renewing subscriptions and free trials. All purchases are processed by the Apple App Store or Google Play, not by TennisLens directly. This means your payment is handled under the app store's own terms and privacy policy. The store holds your payment details. We receive only the information needed to confirm and manage your subscription status. You can manage, cancel, or review your subscription in your app store account settings. Please also see our Terms of Service for the subscription terms.
13. Third-party content and embeds
The app shows curated "Pro Breakdown" videos using TikTok's official embedded player. When such a video loads, your device communicates directly with TikTok to stream the video, and TikTok may set cookies or collect information through its player in accordance with TikTok's own privacy policy. We do not send TikTok your TennisLens data. These embeds are provided for educational purposes and are subject to TikTok's terms.
14. Your rights
Under the UK GDPR you have the following rights in relation to your personal information:
- Access: ask for a copy of the personal information we hold about you.
- Rectification: ask us to correct inaccurate or incomplete information.
- Erasure: ask us to delete personal information in certain circumstances.
- Restriction: ask us to limit how we use your information in certain circumstances.
- Portability: receive certain information in a portable format.
- Objection: object to processing based on our legitimate interests.
- Withdraw consent: where we rely on consent, withdraw it at any time.
Because the Service is anonymous and we do not keep your clips, your on-device history, or an account, we often hold little or no personal information that can be linked to you, which may limit our ability to identify data in response to a request. You can remove your on-device information yourself at any time by clearing the app's data or uninstalling. To exercise any right, contact us at tennislens@moonshard.co. We will respond within the time limits required by law. There is normally no charge.
Accounts, deletion, and withdrawing consent
TennisLens does not offer user accounts, so there is no account to delete. You remain in control of your information at all times:
- Delete your data:remove everything stored by the app by clearing the app's data in your device settings or by uninstalling the app. Because we do not retain your clips, notes, or an account, this removes the information associated with your use.
- Withdraw consent / permissions:you can revoke the camera, microphone, or photo library permissions at any time in your device's settings. The related features will stop working, but the rest of the app will continue to function.
- Cancel subscriptions: manage or cancel any subscription in your Apple App Store or Google Play account settings.
15. Security
We use reasonable technical and organisational measures to protect information, including encryption in transit (HTTPS), reputable infrastructure providers, and the principle of minimising what we collect and retain. No method of transmission or storage is completely secure, but not retaining clips and not operating accounts significantly reduces the risk to your information.
16. Children
The Service is not directed to children under 13, and we do not knowingly collect personal information from children under 13. If you are under 18, you should review this policy and the Terms with a parent or guardian. If you believe a child has provided us with personal information, please contact us and we will take appropriate steps.
17. The TennisLens website and cookies
The TennisLens website is an informational site that provides information about the app and this policy. It does not analyse clips, it does not accept uploads, and it has no connection to our analysis backend. It does not use advertising or third-party tracking cookies and uses only what is strictly necessary to function.
18. Changes to this policy
We may update this policy from time to time. When we do, we will revise the "Last updated" date at the top of this page, and for significant changes we will provide a more prominent notice where appropriate. Your continued use of the Service after an update means you accept the revised policy.
19. How to contact us and complain
For any privacy question or to exercise your rights, contact Moon Shard Ltd at tennislens@moonshard.co. For help using the app, visit our support page.
If you are in the UK and you believe we have not handled your information properly, you have the right to complain to the Information Commissioner's Office (ICO). You can contact the ICO at ico.org.uk or on 0303 123 1113. We would, however, appreciate the chance to address your concerns first.