Terms of Use and
Service Conditions

Parties and Subject

This agreement is concluded between the person who downloads and uses the YiYo app (the "User") and the app's developer, Hasan Karsi (the "Service Provider"; Türkiye, e-mail: [email protected]), in order to set out the terms of use. By downloading the app and creating an account, the User declares that they have read and accepted this agreement, the Privacy Policy, the Explicit Consent Statement and the Medical Disclaimer below.

Scope of the Service

YiYo is a mobile app intended to make nutrition tracking easier and consists of the following modules:

• Profile and plan creation: Calculating a daily calorie target from the information the user provides and generating a 1-day, 1-week or 1-month meal plan.
• Daily tracking: Meal completion status, calorie and macronutrient tracking, water intake logging.
• Photo-based calorie analysis: Analysing a meal photo taken or selected from the gallery with an image model to produce estimated nutritional values.
• Barcode scanning: Scanning a packaged product's barcode to retrieve nutritional values from the Open Food Facts open database.
• Recipe suggestions: Generating recipes from the ingredients the user selects, respecting their preferences and restrictions; saving recipes as favourites and adding them to the plan.
• Weekly and monthly summaries: Summarising tracking data and providing AI commentary on those summaries.
• Reminders: Scheduling meal, water and movement reminders on the device.
• Support: Sending and receiving answers to support requests from within the app.

The Service Provider reserves the right to develop, change or remove modules.

Conditions of Use and Age Limit

Because YiYo processes health data, it is intended for users aged 18 or over. Users aged 13 to 17 may use the app only with the consent and under the supervision of a legal parent or guardian; for these users, the Explicit Consent Statement must be given by the parent or guardian or with their approval. Children under 13 may not use the app.

The app is not specifically designed for people who are pregnant or breastfeeding, who have a history of eating disorders, or who have serious chronic conditions. In such cases the app's suggestions should only be evaluated under the supervision of a physician or dietitian.

Account Creation and Authentication

• The app cannot be used without an account. An account can be created with an e-mail address and password, or with a Google or Apple account.
• Users who register by e-mail cannot sign in before verifying their e-mail address.
• The User is responsible for the security of their own account and password. A User who notices unauthorised use must inform the Service Provider immediately.
• Each user may only open an account in their own name; transferring or sharing an account with third parties is prohibited.

AI Limitations and Accuracy

YiYo produces results by processing the data entered by the user through third-party artificial intelligence (AI) algorithms and image processing models.

• Calorie values, dish recognition results (camera analysis), nutritional data returned from external databases via barcode, generated recipes and nutrition plans are not 100% accurate; they are estimates.
• In photo analysis, portion and weight estimates may deviate noticeably from reality depending on lighting, angle and the visibility of the items on the plate.
• Barcode results come from an open, community-maintained database; product information may be incomplete, outdated or incorrect.
• The app does not guarantee the accuracy of information from integrated services or of AI predictions.
• The User confirms portions and calories entirely at their own discretion and responsibility, and is expected to review the values before saving them.

Medical Disclaimer

YiYo is not a healthcare institution, a dietitian or a medical doctor. The nutrition plans, macro and micronutrient calculations, water targets, recipes and AI comments offered in the app are for informational purposes only; they are not a substitute for professional medical advice, diagnosis or treatment.

The allergy and chronic condition information you enter (diabetes, blood pressure, thyroid, etc.) is taken into account when the algorithm produces general results; however, this does not mean the generated content is safe for your health condition. If you have an allergy, you must verify the contents of every suggested recipe and product yourself.

Before starting any diet programme, changing your eating habits or making decisions that could affect your medication or treatment, you should consult a physician or a licensed dietitian. In a medical emergency, call emergency services rather than using the app.

User Obligations

• The User must provide accurate and up-to-date information in their profile. Incorrect height, weight, age or health information directly affects the generated plan.
• The app may not be used for unlawful purposes, with another person's data, or through automated tools (bots, scripts).
• No attempt may be made to overload the service, to call server functions outside their purpose, or to circumvent security measures.
• No insulting, rights-infringing or unlawful content may be submitted in any text entered into the app, including support requests.

Pricing

YiYo is currently free; it contains no subscription, in-app purchase, locked feature or advertising. The Service Provider reserves the right to offer paid features in the future; in that case the pricing terms will be announced in advance and no retroactive charge will be made for past free use.

Third-Party Services

The app uses Google Firebase for authentication and data storage, Groq for AI generation and image analysis, Open Food Facts for packaged product information, and Apple and Google services for optional sign-in methods. If these services are interrupted, change their scope or are discontinued, the related modules may stop working temporarily or permanently. The terms and privacy policies of those providers apply to their own services.

Continuity of the Service

The Service Provider does not undertake that the app will operate uninterrupted and error-free. The service may be suspended temporarily for maintenance, updates, infrastructure failures or force majeure. Apart from the parts of the app that work offline, modules requiring an internet connection (plan generation, photo analysis, barcode lookup, recipe generation, backup) cannot be used without a connection.

Intellectual Property

The design, code, interface, logos, mascot and generated plan templates of the app belong to the Service Provider. They may not be reverse engineered, copied or reproduced for commercial purposes.

Data entered and photos uploaded by the User belong to the User. The Service Provider uses this content solely to deliver the service, within the scope described in the Privacy Policy; it does not use it for marketing and does not sell it to third parties.

Limitation of Liability

The Service Provider cannot be held liable for health problems arising from use of the app and from following its nutrition plans, for decisions taken on the basis of inaccurate calorie estimates, or for indirect damages. This limitation does not cover liability arising from intent, gross negligence or mandatory provisions of consumer legislation.

Termination of the Account

The User may at any time delete their account, plan history and profile data via the "Delete Account" option on the Profile page in the app. Deleted data cannot be recovered. See Account Deletion for details.

The Service Provider may suspend or close an account in case of breach of this agreement, misuse of the service or unlawful use.

Changes

The Service Provider reserves the right to change the app's features, the AI models used or the terms of this agreement. The current text is always published on this page. Changes that materially affect the User's rights and obligations are announced in the app; a User who does not accept a change may terminate the agreement by deleting their account.

Governing Law and Dispute Resolution

Turkish law applies to this agreement. The courts and enforcement offices of the Republic of Türkiye have jurisdiction; users who qualify as consumers retain the right to apply to Consumer Arbitration Committees and Consumer Courts within the applicable monetary limits. The parties will first try to resolve disputes via [email protected].