Privacy Policy: GainLogic

Privacy policy for GainLogic

GainLogic (“we”, “our”, or “the app”) is engineered with an uncompromising privacy-first and local-first architecture. All workout logs, routines, and physical stats remain stored exclusively on your device. We operate no cloud user accounts, tracking pixels, or telemetry databases.

1. Data stored locally on your device

• Workout and training data: All exercise routines, set logs, weights, repetitions, rate of perceived exertion (RPE), rest timers, and workout notes are stored strictly on your device within a private SQLite database.
• Biometric profile data: Personal stats such as age, height, body weight, sex, training experience, injury history, and target goals are stored exclusively on your device.
• API keys: If you configure Direct API mode, your API keys are stored encrypted on your device using Android Keystore hardware-backed encryption.

We do not operate backend user accounts, sync servers, or analytics databases. We do not sell, rent, or monetise your personal data.

2. External AI connectivity and third-party data privacy

GainLogic offers optional AI capabilities to help plan routines, analyse training progression, and refresh exercises without recurring subscriptions. You can use these features through two mechanisms:

• Native clipboard chat bridge: Prompts are formatted locally on your device and copied to your clipboard. You manually paste the prompt into your preferred external chat application (e.g., ChatGPT, Claude, Gemini). Data handling is governed solely by your agreement with that third-party service.
• Direct API mode (bring your own key): If you provide your own API key, GainLogic transmits prompt payloads directly from your mobile device to your chosen AI provider (such as OpenAI, Anthropic, Google Gemini, OpenRouter, or a custom self-hosted endpoint) over secure HTTPS.

3. Understanding data privacy risks with external LLM providers

While GainLogic does not intercept, proxy, log, or store your prompts on any intermediary server, using external large language models (LLMs) via your own API key introduces important data privacy considerations that you should understand:

• Direct transmission to third parties: When you trigger an AI prompt, data leaves your device and is processed by the external LLM provider you selected. We do not intermediate this connection.
• Payload contents: Depending on the prompt, the transmitted data includes exercise names, target muscle groups, set/rep ranges, and previous workout performance. If you have enabled profile sharing, it may also include personal metrics such as your age, body weight, training level, and relevant injury notes.
• Provider data policies and model training: Each AI provider enforces its own commercial data governance and retention policies. While developer API terms for major providers (such as OpenAI API, Anthropic API, or Google Cloud Vertex AI) generally stipulate that API inputs are not used to train foundation models, retention windows for abuse monitoring (typically 30 days) may still apply. Consumer web chat interfaces often operate under different terms. You are solely responsible for reviewing and accepting the terms and privacy practices of your chosen AI provider.
• Self-hosted and local alternatives: To eliminate third-party data exposure entirely, GainLogic supports custom endpoint URLs. You can point the app to a local LLM instance (such as Ollama or LocalAI running on your home network or private server), ensuring no training logs or biometric data ever leave your personal infrastructure.

4. User privacy controls and profile redaction

You maintain continuous control over what data is shared with external models:

• Profile redaction toggle: In Settings, you can disable “Share profile with AI” at any time. When disabled, GainLogic strictly redacts all personal stats, age, body weight, and health notes from prompt templates, sending only generic exercise variables.
• Key revocation: You can delete stored API keys instantly from the app settings, which purges the credentials from the on-device secure keystore.

5. Data retention, export, and user erasure rights

Because your data is stored locally on your device, you have complete sovereignty and control:

• Data export: You can export your entire exercise history and profile as structured JSON or CSV files at any time via Settings > Import & Export.
• Data deletion: You can permanently delete all workouts, logs, and settings by clearing app storage in your Android system settings or by uninstalling the application.

6. Contact and privacy governance

For any questions regarding this privacy policy or our data practices, contact:

4DC Services
Email: alex@4dc.services
Website: https://4dc.services