Privacy Policy

Prevolut Ltd ("we", "us", "our") develops and publishes Chapper, an iOS application that allows users to connect to their own local or self-hosted large language model (LLM) servers. This Privacy Policy explains our data practices for the Chapper application.

Chapper is designed from the ground up as a privacy-first application. We do not operate servers that process your conversations. We do not collect telemetry or usage analytics. We do not receive the messages you send or the responses you receive.

This policy is written in plain English and in compliance with the UK General Data Protection Regulation (UK GDPR), the Data Protection Act 2018, and Apple's App Store Privacy requirements.

Chapper does not collect, transmit, store, or process any of the following on behalf of Prevolut Ltd:

• Conversation content — messages you send and AI responses you receive are processed entirely between your device and the server you configure. Prevolut Ltd has no access to this data.
• Usage analytics — we do not embed any analytics SDK (e.g. Firebase, Amplitude, Mixpanel, or similar). No usage events, screen views, taps, or session data are sent to us.
• Crash reports — we do not use a third-party crash reporting service. Crashes are reportable only through Apple's standard opt-in mechanism, governed entirely by Apple's privacy policy.
• Device identifiers — we do not collect your Advertising Identifier (IDFA), Vendor Identifier (IDFV), or any device fingerprint.
• Location data — Chapper does not request or access your location.
• Contact information — we do not collect your name, email address, phone number, or any other contact detail unless you voluntarily provide it via feedback (see below).
• Photos or media — Chapper does not access your photo library, camera, or microphone beyond the in-app speech-to-text feature, which processes audio locally on your device via Apple's AVSpeechRecognition framework.

All core functionality in Chapper operates locally on your device or communicates directly with a server that you own and configure.

Conversation data

Messages and conversation history are stored exclusively in a local Core Data database on your device. This database is sandboxed within Chapper's private container and is not accessible to other applications. If you enable iCloud backup (via iOS Settings), your device backup may include this database; this is governed by Apple's iCloud Terms and Privacy Policy, not ours.

LLM server connection

When you send a message, Chapper connects directly to the server address you have entered in Settings (typically a local network address or a private server via VPN/Tailscale). Prevolut Ltd does not operate any relay, proxy, or intermediary service. We never have access to your server address, your API key, or any data transmitted between the app and your server.

On-device speech recognition

The optional speech-to-text feature uses Apple's AVSpeechRecognizer framework. Audio is processed on-device. Prevolut Ltd does not receive audio data.

On-device TTS (Neural Engine)

The optional local text-to-speech feature uses CoreML models downloaded from HuggingFace to your device. All inference runs locally via Apple's Neural Engine. Downloaded model files are stored in Chapper's private container. Prevolut Ltd does not receive or process any audio or text through this feature.

App settings

All settings (server address, API key, sampling parameters, UI preferences) are stored in UserDefaults on your device. They are not transmitted to Prevolut Ltd.

If you choose to contact us for support or to provide feedback — for example by emailing [email protected] or through a future in-app feedback mechanism — you may voluntarily provide personal data such as your name, email address, and a description of your issue.

Any personal data provided in this way will be:

• Used solely to respond to your enquiry or act on your feedback
• Not shared with third parties for commercial purposes
• Retained only for as long as necessary to resolve the matter
• Processed on the legal basis of legitimate interests (Article 6(1)(f) UK GDPR) — specifically, our interest in providing support to users

Submitting feedback is entirely voluntary. The app's core functionality does not depend on it.

This privacy policy covers the Chapper app. The website at prevolut.uk uses Cloudflare Web Analytics, a privacy-focused analytics service provided by Cloudflare, Inc. Cloudflare Web Analytics does not use cookies, does not track individual users across sites, and does not build advertising profiles.

Cloudflare may process anonymised aggregate data (such as page view counts and general geographic region) to provide this service. This data is not linked to your identity and is not accessible to Prevolut Ltd at an individual level. Cloudflare's privacy practices are governed by the Cloudflare Privacy Policy.

No cookies are set by Cloudflare Web Analytics. No consent banner is required under UK GDPR or the UK PECR for cookieless analytics of this nature.

Chapper offers an optional one-time purchase ("Chapper Pro") via Apple's In-App Purchase system (StoreKit). All payment processing is handled exclusively by Apple. Prevolut Ltd does not receive, store, or process your payment card details, Apple ID, or any billing information.

When you make a purchase, Apple provides Prevolut Ltd with a transaction receipt that confirms entitlement. This receipt does not contain personally identifiable information.

Apple's handling of purchase data is governed by the Apple Privacy Policy and the App Store Terms and Conditions.

Chapper is not directed at children under the age of 13 (or the applicable minimum age in your jurisdiction). We do not knowingly collect personal data from children. Because Chapper does not collect personal data from any user, this is largely declaratory — there is no mechanism by which we could inadvertently collect a child's data.

Parents or guardians who believe their child has provided personal data to us should contact [email protected] and we will take appropriate steps.

Under UK data protection law, you have the following rights regarding personal data we hold about you. Because Chapper collects no personal data by default, most of these rights will only be relevant if you have contacted us for support or feedback.

• Right of access — request a copy of any personal data we hold about you.
• Right to rectification — request correction of inaccurate or incomplete data.
• Right to erasure ("right to be forgotten") — request deletion of your data where there is no overriding legitimate reason to retain it.
• Right to restriction of processing — request that we limit how we use your data while a dispute is resolved.
• Right to data portability — receive your data in a machine-readable format where processing is based on consent or contract.
• Right to object — object to processing based on legitimate interests.
• Right to lodge a complaint — you may complain to the UK Information Commissioner's Office (ICO) at ico.org.uk or by phone on 0303 123 1113.

To exercise any of the above rights, please contact us at [email protected]. We will respond within one calendar month as required by UK GDPR Article 12.

Because Chapper does not collect personal data from app usage, there is no retention schedule to describe for app data — it simply stays on your device until you delete it.

For the limited personal data that may be provided voluntarily (e.g. support emails):

• Support correspondence — retained for up to 2 years after the matter is resolved, or deleted sooner upon request
• Purchase receipts — transaction confirmation data provided by Apple is retained for the duration required by UK tax and accounting law (typically 6 years)

You may request deletion of any personal data we hold about you at any time by contacting us. We will comply unless we are legally required to retain it.

We may update this Privacy Policy from time to time. If we make material changes — for example, if we introduce a new feature that involves data collection — we will update the "Last updated" date at the top of this page and, where appropriate, notify users through the app or the App Store release notes.

Continued use of Chapper after any update constitutes acceptance of the revised policy. We encourage you to review this page periodically.

The current version will always be available at prevolut.uk/products/chapper/privacy.

The data controller for Chapper is: