Privacy Policy
Effective Date: July 5, 2026
Last Updated: July 5, 2026
Table of Contents
- Introduction & Scope
- Data Controller
- AI System Disclosure
- Information We Collect
- How We Use Information
- Web Search Feature
- Third-Party Services
- Data Sharing & Disclosure
- Data Retention
- Data Security
- Your Rights
- International Data Transfers
- Children's Privacy
- Do Not Sell or Share
- Model Training & AI Data Use
- Device Permissions
- Website & Cookies
- Open-Source Licenses
- Changes to This Policy
- Contact Us
1. Introduction & Scope
This Privacy Policy describes how Sunday ("we," "us," or "our") handles information when you use the Sunday mobile application for iOS (the "App") and our promotional website at sunday-ai-web.web.app (the "Website"), collectively referred to as the "Services."
Sunday is a private, on-device artificial intelligence assistant. Our core architecture is designed around a single principle: your conversations are yours alone. The AI model runs entirely on your physical device. We do not operate cloud servers that process, store, or have access to your prompts, messages, or AI-generated responses.
By downloading, installing, or using the App, or by accessing the Website, you acknowledge that you have read and understood this Privacy Policy. If you do not agree with this policy, please do not use the Services.
2. Data Controller
For the purposes of the EU General Data Protection Regulation ("GDPR"), the UK GDPR, and other applicable data protection laws, the data controller is:
William Hinz
Email: hinzwilliam52@gmail.com
If you have any questions about how your data is handled, please contact us at the email address above.
3. AI System Disclosure
In accordance with the EU AI Act (Article 50, effective August 2, 2026), we disclose the following:
- Sunday is an AI system. All responses generated within the App are produced by a large language model (Google Gemma 4, 2.5B parameter variant) running locally on your device.
- Sunday's outputs are AI-generated content and should not be treated as human-written, professional advice, or verified facts. Large language models can produce inaccurate, incomplete, or biased outputs.
- The AI model is not connected to the internet and does not access real-time information unless you explicitly enable the optional Web Search feature.
- No human reviews, monitors, or has access to your conversations with Sunday.
4. Information We Collect
4.1 Information Processed Locally on Your Device (Never Transmitted)
The following categories of information are processed and stored exclusively on your iPhone. This data never leaves your device and is never accessible to us, our servers, or any third party:
| Category | Description | Storage |
|---|---|---|
| Conversations | All text prompts, AI responses, and chat history | Local app sandbox |
| Photos & Images | Images you share with the AI for visual analysis | Processed in-memory, not persisted |
| Voice Recordings | Audio captured for speech-to-text transcription | Temporary files, deleted after transcription |
| Video Frames | Frames extracted from videos for AI analysis | Processed in-memory, not persisted |
| App Preferences | Theme color, background, vision quality, video depth, memory compaction settings | iOS UserDefaults (local) |
| Location (City-Level) | Approximate location used to contextualize queries (e.g., "what's the weather") | In-memory only, never persisted or transmitted |
Because this data never leaves your device, it is not considered "collected" under Apple's App Store privacy guidelines, GDPR, or CCPA.
4.2 Information Transmitted to Third Parties
The following data may be transmitted only when you explicitly enable the corresponding feature:
| Feature | Data Transmitted | Recipient | User Control |
|---|---|---|---|
| Web Search | Search query text, your IP address | DuckDuckGo, Open-Meteo, Wikipedia (see Section 6) | Toggle on/off in Settings; off by default |
| Model Download | Standard HTTP request headers (IP address, User-Agent) | Hugging Face (huggingface.co) | One-time initial setup; required for first use |
| Speech Recognition | Audio data for transcription | Apple (via SFSpeechRecognizer; may use Apple servers) | Requires explicit microphone and speech recognition permission |
4.3 Information We Do NOT Collect
We want to be explicitly clear about what we do not collect, access, or process:
- We do not collect advertising identifiers (IDFA) or vendor identifiers (IDFV).
- We do not use analytics SDKs, crash reporting services (such as Firebase Crashlytics or Sentry), or telemetry frameworks.
- We do not collect device fingerprints, hardware identifiers, or system diagnostic data.
- We do not collect usage statistics, session logs, or behavioral data.
- We do not require account creation, email addresses, phone numbers, or any personal identifiers.
- We do not collect model performance telemetry (inference speed, error rates, etc.).
- We do not track you across apps or websites.
5. How We Use Information
| Processing Activity | Purpose | Legal Basis (GDPR Art. 6) |
|---|---|---|
| On-device AI inference | Generate responses to your prompts | Contract performance (providing the service) |
| On-device speech recognition | Convert voice to text for chat input | Consent (you grant microphone permission) |
| On-device image/video analysis | Process visual inputs for multimodal AI | Contract performance |
| Web search queries (if enabled) | Retrieve real-time information from the web | Consent (you explicitly enable the feature) |
| Location access (if permitted) | Contextualize local queries (weather, nearby info) | Consent (you grant location permission) |
| Model weight download | Download AI model files for initial setup | Contract performance (required for app functionality) |
| Preference storage | Remember your chosen settings between sessions | Legitimate interest (basic app functionality) |
6. Web Search Feature
When you explicitly enable the Web Search toggle in the App's settings, the AI may issue outbound network requests to retrieve real-time information. This is the only feature in the App that transmits user-generated content to external servers.
6.1 What Data Is Sent
- Search query text: The specific search terms generated by the AI based on your conversation.
- Your IP address: Automatically included in HTTP requests by your network connection. We do not add additional identifiers.
- User-Agent string: A standard browser identifier header included in HTTP requests.
6.2 Which Services Receive Data
| Service | Purpose | Privacy Policy |
|---|---|---|
| DuckDuckGo | General web search (Instant Answer API & HTML results) | duckduckgo.com/privacy |
| Open-Meteo | Weather data (free, no API key required) | open-meteo.com/en/terms |
| Wikipedia | Encyclopedia summaries (Wikimedia REST API) | Wikimedia Privacy Policy |
6.3 User Control
- Web Search is disabled by default. No search queries are ever sent unless you explicitly enable the toggle.
- You can disable Web Search at any time by toggling the setting off. All future queries will be processed entirely offline.
- When Web Search is disabled, the App makes zero outbound network requests (except the one-time model download during initial setup).
7. Third-Party Services
The App integrates the following third-party services. We do not use any advertising networks, analytics platforms, or tracking SDKs.
| Service | Purpose | Data Shared |
|---|---|---|
| Hugging Face | Model weight hosting & download | IP address, HTTP headers (one-time download) |
| Apple Speech Framework | Speech-to-text transcription | Audio data (subject to Apple's Privacy Policy) |
| Apple CoreLocation | Approximate device location | Location data stays on-device; reverse geocoding uses Apple services |
| DuckDuckGo, Open-Meteo, Wikipedia | Web search (when enabled) | Search queries, IP address (see Section 6) |
Each third-party service is governed by its own privacy policy. We encourage you to review them.
9. Data Retention
| Data Type | Retention Period | Deletion Method |
|---|---|---|
| Conversations & chat history | Until you delete them or uninstall the App | Clear History in Settings, or delete individual conversations |
| Photos/video frames | Processed in-memory; not persisted | Automatically cleared after processing |
| Voice recordings | Temporary; deleted after transcription | Automatically deleted |
| App preferences | Until you uninstall the App | App deletion removes all UserDefaults |
| Web search queries | Not stored by Sunday; subject to third-party policies | See third-party privacy policies |
| Model weight files | Until you uninstall the App | App deletion removes all local files |
Complete data erasure: Uninstalling the App from your device permanently deletes all locally stored data, including conversations, preferences, and model files. No residual data remains on any server because no data was ever transmitted to one.
10. Data Security
We implement the following security measures to protect your information:
- On-device architecture: The most effective data protection is not collecting data in the first place. All AI processing occurs locally on your device's Apple Silicon GPU.
- iOS App Sandbox: All app data is stored within iOS's sandboxed container, isolated from other apps and protected by iOS's file-level encryption.
- HTTPS encryption: All network communications (model download, web search) use HTTPS/TLS encryption in transit.
- No server-side storage: We do not operate backend servers that store user data. There is no database to breach.
- No remote access: We have no mechanism to remotely access, view, or extract data from your device.
While no system is 100% secure, our on-device architecture significantly reduces the attack surface compared to cloud-based AI services.
11. Your Rights
11.1 Rights Under the EU/UK GDPR
If you are located in the European Economic Area (EEA), the United Kingdom, or Switzerland, you have the following rights under the General Data Protection Regulation:
- Right of Access (Art. 15) — Request confirmation of whether we process your personal data and obtain a copy.
- Right to Rectification (Art. 16) — Request correction of inaccurate personal data.
- Right to Erasure (Art. 17) — Request deletion of your personal data ("right to be forgotten").
- Right to Restrict Processing (Art. 18) — Request limitation of processing in certain circumstances.
- Right to Data Portability (Art. 20) — Receive your data in a structured, machine-readable format.
- Right to Object (Art. 21) — Object to processing based on legitimate interests.
- Right to Withdraw Consent (Art. 7) — Withdraw consent at any time where processing is based on consent (e.g., disable Web Search).
- Right to Lodge a Complaint — File a complaint with your local Data Protection Authority (DPA).
Practical note: Because Sunday does not collect or store personal data on our servers, most of these rights are automatically satisfied. All your data resides on your device under your exclusive control. You can exercise your right to erasure at any time by clearing your chat history or uninstalling the App.
11.2 Rights Under California Law (CCPA/CPRA)
If you are a California resident, the California Consumer Privacy Act (as amended by the California Privacy Rights Act) provides you with additional rights:
- Right to Know: You have the right to know what personal information we collect, use, disclose, and sell.
- Right to Delete: You have the right to request deletion of personal information we have collected.
- Right to Correct: You have the right to request correction of inaccurate personal information.
- Right to Opt-Out of Sale/Sharing: See Section 14 ("Do Not Sell or Share").
- Right to Limit Use of Sensitive Personal Information: You may limit the use of sensitive personal information to purposes necessary for providing the services.
- Right to Non-Discrimination: We will not discriminate against you for exercising any of these rights.
To exercise any of these rights, contact us at hinzwilliam52@gmail.com. We will respond within the legally required timeframe (45 days for CCPA; one month for GDPR, extendable by two months for complex requests).
11.3 Global Privacy Control
We honor Global Privacy Control (GPC) browser signals. If your browser sends a GPC signal, we treat it as a valid opt-out request under applicable laws.
12. International Data Transfers
When the Web Search feature is enabled, search queries may be transmitted to servers located outside your country of residence, including servers in the United States and other jurisdictions.
For users in the EEA/UK/Switzerland, we rely on the following legal mechanisms for international data transfers:
- Standard Contractual Clauses (SCCs) adopted by the European Commission, where applicable.
- Adequacy decisions issued by the European Commission for countries deemed to provide adequate data protection.
- Consent: By enabling Web Search, you provide informed consent to the transfer of your search queries to the third-party services listed in Section 6.
You can prevent any international data transfer by keeping the Web Search feature disabled (its default state).
13. Children's Privacy
Sunday is designed as a general-audience application. We do not direct the App toward children under the age of 13 (or the applicable age of digital consent in your jurisdiction).
- We do not knowingly collect personal information from children under 13.
- Because Sunday processes all data on-device and does not collect personal information from any user, the risk of inadvertent collection of children's data is minimal.
- If the Web Search feature is enabled and we learn that a child under 13 has used it, we will take steps to ensure compliance with the Children's Online Privacy Protection Act (COPPA), including notifying the parent or guardian.
- Parents or guardians who believe their child may have used the Web Search feature can contact us at hinzwilliam52@gmail.com for assistance.
14. Do Not Sell or Share My Personal Information
As required by the California Consumer Privacy Act (CCPA/CPRA):
We do not sell your personal information. We have not sold personal information in the preceding 12 months.
We do not share your personal information for cross-context behavioral advertising purposes. We have not shared personal information for such purposes in the preceding 12 months.
We do not engage in the "sale" or "sharing" of personal information as those terms are defined under the CCPA. We do not use advertising networks or data brokers.
15. Model Training & AI Data Use
Your data is never used to train, fine-tune, or improve any AI model.
- Sunday uses a pre-trained, static model (Google Gemma 4) that is downloaded once and runs locally. The model weights do not change based on your usage.
- Your conversations, prompts, images, voice recordings, and AI responses are never transmitted to us, Google, or any third party for model training purposes.
- We do not collect feedback data, thumbs-up/down ratings, or conversation quality signals for model improvement.
- The model cannot "learn" from your conversations between sessions. Each session uses the same base model weights.
16. Device Permissions
Sunday requests the following iOS permissions. Each permission is optional and requested only when you use the corresponding feature:
| Permission | Purpose | Data Handling |
|---|---|---|
| Camera | Capture photos for AI visual analysis | Processed on-device; never transmitted |
| Microphone | Record voice for speech-to-text | Temporary recording; transcribed locally via Apple Speech framework |
| Speech Recognition | Transcribe spoken words to text | Processed via Apple's SFSpeechRecognizer (may use Apple's servers per Apple's privacy policy) |
| Location (When In Use) | Provide local context (e.g., weather for your city) | Reduced accuracy (city-level); stays on-device; never stored or transmitted by Sunday |
| Files & Documents | Import documents for AI analysis | Processed on-device; never transmitted |
You can revoke any permission at any time through iOS Settings → Sunday. Revoking a permission will disable the associated feature but will not affect the core AI chat functionality.
17. Website & Cookies
Our promotional website at sunday-ai-web.web.app is a static site hosted on Firebase Hosting (operated by Google LLC).
17.1 What We Use
- localStorage: We use browser localStorage solely to save your chosen theme color and background preferences for the interactive demo. This data is stored locally in your browser and is never transmitted to any server.
- Firebase Hosting: Google's Firebase Hosting serves our static files via a global CDN. Standard HTTP server logs (IP address, requested URL, timestamp, User-Agent) may be collected by Google as part of Firebase Hosting infrastructure per Firebase's Privacy Policy.
17.2 What We Do NOT Use
- We do not use Google Analytics, Facebook Pixel, or any analytics or advertising scripts.
- We do not set tracking cookies or advertising cookies.
- We do not use session replay tools, heatmaps, or behavioral analytics.
- We do not embed third-party social media trackers or "like" buttons.
17.3 Cookie Consent
Because we only use localStorage for strictly necessary functionality (saving your theme preference for the demo), and do not use cookies for tracking, profiling, or advertising, a cookie consent banner is not required under the ePrivacy Directive. If our practices change, we will implement appropriate consent mechanisms.
18. Open-Source Licenses
Sunday uses the following open-source software:
- Google Gemma 4 (gemma-4-e2b-it) — Licensed under the Apache License 2.0. The model is developed by Google DeepMind. Google does not receive any user data through Sunday's use of the Gemma model.
- MLX Framework — Apple's machine learning framework for on-device inference.
Use of the Gemma model is subject to the Gemma Terms of Use. By using Sunday, you agree to comply with these terms.
19. Changes to This Policy
We may update this Privacy Policy from time to time to reflect changes in our practices, legal requirements, or the Services. When we make material changes:
- We will update the "Last Updated" date at the top of this page.
- For significant changes that affect your rights, we will provide prominent notice (such as an in-app notification or a banner on the Website).
- We will maintain prior versions of this policy available upon request.
We encourage you to review this Privacy Policy periodically. Your continued use of the Services after changes constitutes acceptance of the updated policy.
20. Contact Us
If you have any questions, concerns, or requests regarding this Privacy Policy, your personal data, or Sunday's privacy practices, please contact us:
Email: hinzwilliam52@gmail.com
Subject Line: "Sunday Privacy Inquiry"
We will acknowledge your request within 5 business days and provide a substantive response within the timeframes required by applicable law.