Terms of Use

HealthSync is provided to you free of charge as part of itsmarian's projects. Under the terms of this Agreement, you are authorised to use the app, its features and any associated content for personal, non-commercial purposes. Selected parts of the source code may additionally be available under an open-source licence (e.g. the MIT Licence); where applicable, the relevant licence file governs your use of that part.

Please read this agreement carefully, as it explains how, for what purposes, under what conditions and with what restrictions you may use the app and services offered at https://healthsync.itsmarian.dev (hereinafter "HealthSync", "the app", "our", "we") by Marian D. (also known as itsmarian, itsmarian.mc or itsmarianmc; hereinafter "I", "me", "my").

By continuing, you confirm that you have read and agree to the Privacy Policy, the Cookie Policy, the AI Guidelines and these Terms of Use. If you do not agree, please leave HealthSync and refrain from using its features.

Last updated: 18 June 2026

1.1 These Terms of Use govern the use of HealthSync, available at https://healthsync.itsmarian.dev and any associated sub-pages, APIs and services. HealthSync is a personal project and part of itsmarian's projects. In order to use HealthSync, you accept these Terms of Use.

1.2 By using HealthSync, you agree to these Terms of Use and warrant that you will not engage in any conduct that violates them.

1.3 The features provided by HealthSync include, but are not limited to:

• Calorie and macro tracking (CalSync), including manual entry, barcode scanning via Open Food Facts and optional AI-assisted nutrition estimation.
• Hydration tracking (DropSync) with quick logging and history.
• Workout logging with routines, live session timer and set tracking.
• A personal dashboard with daily score, recent log and trend chart.
• Optional cloud synchronisation across devices via a user account.

If you have any questions regarding HealthSync or these Terms of Use, you may contact me using the following details:

Marian D. (also known as itsmarian / itsmarian.mc / itsmarianmc)
Germany
E-mail: support@itsmarian.dev
Legal notice / imprint: https://itsmarian.dev/imprint

3.1 I endeavour to ensure the availability of HealthSync at all times. However, temporary interruptions may occur due to scheduled maintenance, system updates, or circumstances beyond my control. I will make reasonable efforts to limit the frequency and duration of any such interruptions.

3.2 I expressly note:

• That errors may result in the temporary unavailability of the app or of cloud synchronisation.
• That it is technically not possible to guarantee software entirely free of errors, and I therefore accept no liability in this respect beyond the limits set out in #11 (Liability).
• That the availability of HealthSync depends on conditions and services outside of my control, including the hosting provider, the authentication/database provider and your own network and device. I am not responsible for disruptions in those areas.
• That HealthSync is a personal project. Features may be added, modified or removed at any time as the app evolves.

4.1 HealthSync can be used without an account; in that case, your data remains locally in your browser. To synchronise data across devices, you may create a free user account.

4.2 You are responsible for keeping your login credentials confidential and for all activity that occurs under your account. You agree to notify me without undue delay if you become aware of any unauthorised use of your account.

4.3 I strongly recommend enabling Two-Factor Authentication (TOTP) where available.

4.4 You may delete your account at any time from within the app. Deleting your account removes the data associated with your user ID from the cloud backend, subject only to statutory retention obligations.

5.1 You agree to use HealthSync only for lawful personal purposes and in accordance with these Terms of Use. In particular, you agree not to:

5.2 I may, at my reasonable discretion, suspend or terminate access to HealthSync in response to violations of these Terms of Use.

6.1 HealthSync is a personal tracking tool. It is not a medical device, it does not provide medical advice, diagnosis or treatment, and it is not certified under the EU Medical Device Regulation (MDR) or any comparable framework.

6.2 The calorie, macro and hydration goals suggested or calculated by HealthSync (e.g. via the Mifflin–St Jeor formula) are indicative only and may not reflect your individual nutritional needs. Always consult a qualified health professional before making significant changes to your diet, hydration or training routine, in particular if you have any medical condition, are pregnant or breastfeeding, or are under 18.

6.3 You are solely responsible for how you act on information displayed by HealthSync. I accept no liability for decisions or actions taken on the basis of HealthSync data, within the limits set out in #11 (Liability).

7.1 HealthSync offers optional AI-assisted features, in particular nutrition estimation from photos, camera input or text descriptions via Google's Gemini API. These features are strictly opt-in, disabled by default, and require your own Gemini API key.

7.2 By enabling AI Detection you confirm that you have read and accept the AI Guidelines and that you will use the feature in accordance with Google's Gemini API Terms.

7.3 AI output is an estimate and may be inaccurate. You must verify critical nutrition information before relying on it. See #6 (Health-related content) and the AI Guidelines for further details.

When you use HealthSync or send e-mails to me, you are communicating electronically. I will communicate with you electronically, including via e-mail, in-app notices, or notices on the website. For contractual purposes, you agree to receive electronic communications from me and acknowledge that all notices, disclosures and other communications provided electronically satisfy any legal requirement that such communications be made in writing, unless mandatory applicable law expressly requires a different form.

9.1 Unless otherwise stated, all content included in or made available through HealthSync - such as the user interface, text, graphics, logos, icons, images and data compilations - is the property of itsmarian or of third parties who supply or make such content available, and is protected by German and international copyright and database right laws.

9.2 You may not systematically extract or re-utilise substantial parts of the content available at https://healthsync.itsmarian.dev without my express prior written consent. In particular, you may not use data mining, automated scripts, robots or similar data gathering tools to extract substantial portions of HealthSync, nor create and publish your own database or service incorporating substantial parts of my content, without such consent.

9.3 Selected parts of HealthSync's source code may be published under an open-source licence (e.g. the MIT Licence). Where this is the case, the terms of the applicable licence govern your use of those parts. Please refer to the licence file included with each project for details.

9.4 Third-party libraries used by HealthSync (e.g. Next.js, Supabase client, ZXing barcode library, DM Sans font, Font Awesome icons, exercise data) remain the property of their respective owners and are subject to their respective licences.

I respect the intellectual property rights of others. If you believe that content available in HealthSync infringes your intellectual property rights, please contact me at support@itsmarian.dev with a description of the alleged infringement and sufficient information to identify the material concerned. I will investigate all legitimate notices and respond accordingly.

11.1 HealthSync is provided free of charge. I endeavour to ensure that the service is available without interruption and that transmissions are error-free. However, due to the nature of the internet and the experimental nature of some features, this cannot be guaranteed.

11.2 I shall be liable without limitation where the cause of damage is based on an intentional or grossly negligent breach of duty by me.

11.3 I shall further be liable for the slightly negligent breach of material obligations. Material obligations are those whose breach endangers the purpose of the agreement or whose fulfilment is essential to its proper performance and upon which you may reasonably rely. In such cases, however, my liability is limited to the foreseeable damage typical for this type of agreement. I am not liable for the slightly negligent breach of non-material obligations.

11.4 The above limitations of liability shall not apply in the event of injury to life, body or health, in the case of a defect following the assumption of a guarantee for the quality of a product, or in the event of fraudulently concealed defects. Statutory liability under the Product Liability Act (Produkthaftungsgesetz) remains unaffected.

11.5 To the extent that my liability is excluded or limited, this also applies to the personal liability of any persons acting on my behalf.

11.6 I assume no liability for loss of data caused by the loss or destruction of your local device, by clearing your browser's storage, by misconfiguration on your part, or by outages of third-party providers (e.g. hosting or authentication provider). You are responsible for backing up data that is important to you.

11.7 I assume no liability for the accuracy of AI-generated nutrition values, third- party data sources (e.g. Open Food Facts) or any decisions you make on the basis of such data. See #6 and #7 above.

HealthSync contains links to third-party websites. These are provided for convenience and informational purposes only. I assume no liability for and am not responsible for the content of any linked third-party website; responsibility for that content lies solely with the respective operator. If you encounter a broken or incorrect link, please notify me at support@itsmarian.dev so that I may address it promptly.

13.1 Information on how I process personal data in connection with HealthSync is set out in the Privacy Policy. Because HealthSync may process data concerning your health within the meaning of Art. 9 GDPR, please read that policy carefully.

13.2 As a data subject under the GDPR, you hold rights including the right of access, the right to rectification, the right to erasure and the right to restriction of processing, among others. Full details are set out in the Privacy Policy.

13.3 Please note that the transmission of data over the internet may involve security risks. Complete protection against access by third parties cannot be fully guaranteed.

14.1 HealthSync uses a small number of cookies and similar browser-storage technologies. Strictly necessary cookies (e.g. for authentication) are used on the basis of legitimate interest; all other cookies are used only with your prior consent through the cookie banner.

14.2 Full details on the cookies used, their purpose and their retention periods are provided in the Cookie Policy.

No failure or delay by me in exercising any right or provision under these Terms of Use shall constitute a waiver of that right or provision. If I do not act in response to a breach of these Terms of Use on one occasion, I retain the right to enforce these Terms of Use in full on any subsequent occasion.

16.1 These Terms of Use are governed by the laws of the Federal Republic of Germany. The language of this agreement is English. Mandatory consumer-protection provisions of your country of residence remain unaffected.

16.2 I reserve the right to amend these Terms of Use at any time. The version of the Terms of Use in effect at the time you access or use HealthSync shall apply to your use. Continued use of HealthSync following the publication of amended terms constitutes your acceptance of those amendments. Where changes are material, I will endeavour to provide reasonable notice.

16.3 Should any individual provision of these Terms of Use be or become invalid or unenforceable, the remaining provisions shall continue in full force and effect. The invalid or unenforceable provision shall be replaced by a legally permissible provision that most closely reflects the intent and purpose of the original.