Stackdd

Terms of Service

Last updated: 3 June 2026

These Terms of Service ("Terms") govern your use of the Stackdd PT mobile application (the "App") and the stackdd.store website (the "Site"), together the "Service", provided by Certi Technologies Ltd, trading as Stackdd ("we", "us", "our").

By creating an account, downloading the App, or using the Service, you agree to these Terms. If you do not agree, do not use the Service.

1. About us

  • Legal entity: Certi Technologies Ltd, trading as Stackdd
  • Registered office: <<<registered office address>>>
  • Company number: <<<UK company registration number>>>
  • Support contact: support@stackdd.store

2. Eligibility

You must be at least 18 years old to use the Service. By using the Service you confirm that you are 18 or older and have the legal capacity to enter into a binding contract.

You must be physically capable of safe exercise. If you have any medical condition that may affect your ability to exercise or follow nutritional guidance, consult a qualified medical professional before using the Service.

3. The Service

Stackdd PT provides AI-driven personal training and nutrition coaching for general fitness and body-composition goals. The Service includes:

  • An AI coach feature ("Coach") that generates training, nutrition, and recovery guidance
  • Training plans and a library of exercises with demonstration media
  • Daily and weekly check-ins
  • Nutrition tracking, recipe library, and meal logging
  • Apple Health integration (optional, on iOS)
  • Subscription-based access (see Section 5)

We may change, suspend, or discontinue any part of the Service at any time. We will give reasonable notice of material changes that affect paying subscribers.

4. Your account

You are responsible for:

  • Keeping your account credentials secure
  • All activity that occurs under your account
  • Providing accurate information during sign-up and onboarding
  • Notifying us immediately if you suspect unauthorised access

We may suspend or terminate your account if you breach these Terms (see Section 13).

5. Subscriptions and payment

5.1 Plans

The Service is offered on a subscription basis. Current plans are:

  • Standard — £19.99 / month
  • Premium — £32 / month
  • Annual variants — see in-App pricing at the time of purchase

Pricing may change. Existing subscriptions continue at the price you signed up at until renewal; you will be notified of any price change before it takes effect at renewal.

5.2 Free trial

We offer a 7-day free trial for new subscribers. During the trial you have full Premium access. At the end of the trial, you select your plan; you are charged from that point unless you cancel before the trial ends.

5.3 Where you pay

  • In the App (iOS) — payment is processed by Apple under their standard App Store terms. Apple, not Stackdd, is your contracting party for the payment transaction.
  • On the Site (planned, not yet active) — payment will be processed by Stripe Payments UK Ltd. We will be your contracting party for the payment transaction.

5.4 Auto-renewal

Subscriptions renew automatically at the end of each billing period unless you cancel at least 24 hours before the renewal date.

  • For App-based subscriptions: cancel through iOS Settings → [your name] → Subscriptions.
  • For Site-based subscriptions (when available): cancel through your account dashboard at stackdd.store.

You will be charged the renewal price for your selected term until you cancel.

5.5 Cancellation

You may cancel at any time. Cancellation takes effect at the end of the current billing period. You retain access until that point. No partial refunds for unused time.

5.6 Refunds

  • App-based subscriptions: refunds are handled directly by Apple under their App Store refund policy. We have no control over Apple's refund decisions.
  • Site-based subscriptions (when available): if you cancel within 14 days of your first paid charge and have not made substantial use of the Service, we will refund you on request (this is a goodwill policy; statutory rights apply where you have not started using the Service).
  • Free trial: no charge is made during the trial, so there is nothing to refund. Make sure to cancel before the trial ends if you do not want to subscribe.

6. Important — NOT medical or clinical advice

The Service does not provide medical, clinical, psychological, nutritional, or other professional advice or treatment.

Coach is an AI assistant. Its outputs are generated by machine learning models and may be incorrect, incomplete, or unsuitable for your circumstances. Coach is not a doctor, dietitian, registered nutritionist, physiotherapist, psychologist, or any other regulated healthcare professional.

  • Always consult a qualified healthcare professional before starting any new exercise programme, changing your diet significantly, or if you have any medical condition.
  • If you experience pain, dizziness, breathlessness, chest discomfort, or any symptom that concerns you during or after exercise, stop immediately and seek medical attention.
  • Do not rely on the Service to diagnose, treat, cure, or prevent any condition.
  • In an emergency, call 999 (UK) or your local emergency number.

Where Coach detects signals consistent with disordered eating, mental health distress, suicidal ideation, or injury concerns, it may surface external helplines (Beat, MIND, Samaritans, NHS 111). These are signposts only; they are not a substitute for direct contact with those services.

You use the Service at your own risk. To the fullest extent permitted by law, we are not liable for any harm, injury, illness, loss, or damage arising from your use of, or reliance on, Coach outputs or any other part of the Service.

7. AI-generated content

Coach responses, recipe descriptions, weekly recap summaries, plan adjustments, and other outputs may be generated in whole or in part by artificial intelligence.

  • AI outputs may contain errors, factual inaccuracies, or content that does not suit your specific situation.
  • Coach has guardrails for autonomous adjustments (e.g. small calorie nudges); larger changes require your approval through the App.
  • We do not warrant the accuracy, completeness, or fitness for any purpose of any AI-generated output.
  • You are responsible for evaluating Coach guidance before acting on it.

8. Acceptable use

You agree not to:

  • Use the Service for any illegal purpose
  • Attempt to reverse engineer, decompile, or extract source code from the App
  • Probe, scan, or test the vulnerability of any part of the Service
  • Use automated means (bots, scrapers) to access or interact with the Service without our written permission
  • Submit false or misleading information
  • Impersonate any other person
  • Upload content that is unlawful, infringing, harassing, defamatory, obscene, or otherwise objectionable
  • Use the Service to develop a competing product or train competing AI models
  • Resell, sublicense, or transfer your account
  • Circumvent any access controls or subscription limits (e.g. message caps)
  • Use the Service in any way that could damage, disable, overburden, or impair our infrastructure

We may suspend or terminate your account if we reasonably believe you have breached this Section.

9. Your content

You retain ownership of content you upload to the Service (photos, meal logs, check-in answers, messages to Coach, etc. — "Your Content").

By uploading Your Content, you grant us a non-exclusive, worldwide, royalty-free licence to host, store, copy, transmit, and display Your Content strictly for the purpose of providing the Service to you. This licence ends when you delete the content or close your account, except where:

  • We are required to retain it by law (e.g. payment records)
  • It has been incorporated into anonymous, aggregated data that no longer identifies you

We do not use Your Content to train third-party AI models or to advertise to other users.

10. Our intellectual property

The Service, including the App, Site, Coach system prompts, training plans, recipe library, exercise content, branding, and underlying software, is owned by Certi Technologies Ltd and protected by intellectual property laws.

We grant you a limited, non-exclusive, non-transferable, revocable licence to use the Service for your personal, non-commercial use, in accordance with these Terms.

You may not reproduce, distribute, modify, or create derivative works of any part of the Service without our prior written consent.

11. Third-party services

The Service relies on third-party providers (e.g. Supabase, OpenAI, Apple, Google, Stripe, RevenueCat). Your use of those providers may be subject to their own terms and privacy policies. We are not responsible for the practices of third parties, but we choose them carefully and require appropriate data protection commitments.

The Service integrates with Apple HealthKit on iOS subject to your permission. Apple's terms apply to your use of HealthKit.

12. Affiliate programme

We may operate an affiliate programme via the Site (planned, not yet active). Affiliates are subject to a separate Affiliate Agreement. Affiliate commissions are paid only on qualifying subscriptions purchased through the Site; they do not apply to Apple in-App purchases.

13. Termination

You may delete your account at any time via Settings → Account → Delete account.

We may suspend or terminate your account if:

  • You breach these Terms
  • We are required to do so by law
  • We discontinue the Service (we will provide reasonable notice)
  • Your payment is repeatedly declined

On termination:

  • Your access to the Service ends
  • We will delete your personal data in line with our Privacy Policy (Section 6 of that Policy)
  • Sections of these Terms that by their nature should survive (IP, disclaimers, liability, governing law) continue to apply

14. Disclaimers

Except as expressly stated in these Terms and to the extent permitted by law, the Service is provided "as is" and "as available", without warranties of any kind, whether express or implied, including warranties of merchantability, fitness for a particular purpose, or non-infringement.

We do not warrant that:

  • The Service will be uninterrupted, error-free, or secure
  • Coach outputs will be accurate or suitable for your circumstances
  • The Service will achieve any specific fitness, health, body-composition, or weight outcome

Your statutory rights as a consumer under UK law are not affected by these Terms.

15. Limitation of liability

Nothing in these Terms limits or excludes our liability for:

  • Death or personal injury caused by our negligence
  • Fraud or fraudulent misrepresentation
  • Any liability that cannot be limited or excluded under English law

Subject to the above, to the fullest extent permitted by law:

  • We are not liable for any indirect, incidental, consequential, special, or punitive damages
  • We are not liable for loss of profits, revenue, business, goodwill, or data
  • Our total aggregate liability arising out of or in connection with these Terms, whether in contract, tort, or otherwise, is limited to the greater of (a) the amount you have paid us in the 12 months immediately preceding the event giving rise to the claim, or (b) £100.

You acknowledge that the Service is a consumer fitness product priced at a tier that reflects this allocation of risk.

16. Indemnity

You agree to indemnify and hold us harmless from any claim, loss, liability, or expense (including reasonable legal fees) arising out of:

  • Your breach of these Terms
  • Your misuse of the Service
  • Your violation of any law or the rights of any third party
  • Any reliance you place on Coach outputs contrary to the disclaimers in Section 6

17. Changes to these Terms

We may update these Terms from time to time. If we make material changes, we will notify you via the App or by email at least 14 days before they take effect. Continued use of the Service after the effective date constitutes acceptance of the updated Terms.

If you do not accept changes, you may cancel your subscription and stop using the Service.

18. Governing law and disputes

These Terms are governed by the laws of England and Wales.

If you are a consumer resident in the UK, you may bring proceedings in the courts of the part of the UK in which you are resident.

If you are not a consumer, the courts of England and Wales have exclusive jurisdiction over any dispute arising out of or in connection with these Terms.

Before starting any legal proceedings, please contact us at support@stackdd.store — many issues can be resolved informally.

19. General

  • Entire agreement: these Terms (together with our Privacy Policy) form the entire agreement between you and us regarding the Service.
  • Severability: if any part of these Terms is found to be unenforceable, the rest will remain in force.
  • No waiver: our failure to enforce any right is not a waiver of that right.
  • Assignment: you may not assign your rights under these Terms. We may assign ours to a successor entity (e.g. on a corporate restructure or sale of business), giving you reasonable notice.
  • Notices: we may give you notice through the App, by email, or by posting on the Site. You should give us notice at support@stackdd.store.

20. Contact

Certi Technologies Ltd, trading as Stackdd <<<registered office address>>> Company number: <<<UK company registration number>>> Email: support@stackdd.store

These Terms were last reviewed on 3 June 2026. Certi Technologies Ltd, trading as Stackdd.