Lean Privacy Policy

Effective date: July 16, 2026

Lean ("the app") is made by Nexo Development LLC ("we", "us"). This policy explains what information the app handles and where it goes. The short version: your progress photos never leave your device, your daily numbers are only used to run the app's features, and we never sell your information.

What we collect and why

Information you enter

• Quiz answers (age, weight, goal weight, medication type, weeks on medication, time commitment) — used on your device to compute your Muscle-Loss Risk Score, protein target, and daily plan. Stored locally on your device.
• Daily logs (protein, strength sessions, weight, shot day, appetite) — stored locally on your device and used to compute your daily score and coaching.
• Weekly progress photos — stored only on your device. They are never uploaded, never analyzed by us, and are deleted when you delete the app.

AI-personalized coaching (optional, with your consent)

If you turn on AI-personalized coaching, the app sends only the day's numbers — protein grams, protein target, strength sessions, shot-day status, appetite flag, off-ramp status, and the local hour — to our server, which forwards them to our AI provider, Anthropic, to generate your one daily suggestion. This request contains no name, no email, no account ID, no device identifier, and no photos. Anthropic does not use this data to train AI models. You can turn this off any time in Settings → AI coaching, and the app falls back to built-in coaching.

Purchases

Subscriptions are processed by Apple and managed through RevenueCat, our subscription infrastructure provider. RevenueCat receives purchase receipts and an anonymous app-instance identifier so your subscription unlocks correctly. We never see or store your payment details.

Analytics and advertising measurement

• AppsFlyer (attribution): helps us understand which ads brought people to Lean. If you allow tracking in the App Tracking Transparency prompt, this uses your device's advertising identifier (IDFA). If you decline, attribution is limited to aggregate, non-identifying signals.
• PostHog (product analytics): anonymous usage events (e.g. "check-in completed") tied to a random app-generated ID, used to improve the product. No health values are attached to identity.

What we never do

• We never sell your personal information.
• We never use your data to train AI models.
• Your photos never leave your device.
• We never show your information to other users. There are no accounts and no social features.