MacroStack AI ("the App") is a nutrition tracking app for Android. This policy explains what information the App accesses, how it is used, and how your data is protected. We take privacy seriously and collect only what is strictly necessary to provide the app's features.
We do not sell your personal data, and we never will. We have no advertising partners, no analytics providers, and no data brokers. Our only revenue is your payments.
Looking for the iOS privacy policy? View it here. Need help? Visit support.
1. Data Storage On-device only
Your nutrition logs, food entries, weight records, profile information, and goals are stored locally on your device. This log data is never transmitted to us, and we do not maintain any database that stores it. The AI coach and food scanner route limited data through our proxy server to work, see Section 5.
2. Camera & Photo Library Access
The App uses your camera to scan food and barcodes for nutrition tracking. You may also select photos from your photo library for AI-powered food analysis. When you use the AI Food Scanner, your food photo is sent through our proxy server to Google's Gemini API for analysis. We use the paid Gemini API tier, which means Google does not use your photo or the returned analysis to train or improve its products, and does not route them to human reviewers. Google retains the request only for a limited window to detect abuse of its service and to meet legal requirements. The App itself never stores your food photos on our servers. No photos are shared with any third party beyond Google for the single purpose of this analysis. Barcode scanning happens entirely on your device.
3. Location Access
The App requests location access solely to help you find nearby restaurants in the Coach feature. Your location is sent to mapping services to perform the search. No health, nutrition, or fitness data is ever combined with or sent alongside your location. You can deny or revoke location access at any time in your device settings.
4. Health Connect
Health Connect sync is off by default. If you turn it on in Settings → Privacy → Sync with Health Connect and grant the permissions Health Connect asks for (read weight, write weight, write nutrition), the App exchanges these kinds of data with Health Connect on your device:
- Written to Health Connect: your body weight whenever you log, edit, or delete a weigh-in, and each day's total calories, protein, carbohydrates, and fat after any logging change. An edit replaces the earlier record rather than adding to it, and deleting a weigh-in in the App removes the record the App wrote.
- Read from Health Connect: body weight entries that other apps or devices (for example a smart scale) add to Health Connect, so they appear in your weight history and inform your calorie goal. The App reads no other Health Connect data type.
Health Connect data stays on your device, stored by Health Connect. The App uses it only for your weight history, your weekly check-in, and your calorie goal, as described above. It is never sent to our servers or to the AI proxy, never used for advertising, marketing, or profiling of any kind, and never shared with or sold to anyone. Turning sync off stops all reading and writing and leaves what is already in Health Connect untouched. You can also revoke the App's access at any time in Android Settings → Health Connect → App permissions → MacroStack, which stops the sync the same way.
5. AI Features
The App uses cloud-based AI (Google Gemini) to power the nutrition coach and food scanner. When you use these features, your messages and food photos are sent to our proxy server, which forwards them to Google's Gemini API for processing. The data sent includes:
- Your coach messages and questions, including recent turns of the current conversation so the coach can follow the thread
- Your daily calorie and macro context (goal, consumed, remaining)
- When you chat with the coach and Share Log Context is on (Settings > Privacy, on by default): today's logged foods (names, meal slots, portions, calories and macros), the current local time of day (hour only), your fasting eating window and whether it is currently open if you use fasting, and app-computed progress data (average calorie intake, estimated daily burn from your logs, weight trend, and recent goal adjustments). Turning the toggle off keeps all of this out of coach requests, and weekly recaps are then generated on-device instead.
- Saved dietary preferences, if you ask the coach to remember any
- A short list of candidate foods from the app's bundled database, used to keep suggestions grounded
- When you ask for a weekly recap: your last 7 days' averages (calories and macros), days logged, adherence to your goal, logging streak, and your weight change for that week if you logged weigh-ins
- Food photos (for the AI scanner only), along with the labels the on-device image classifier found in them
- A food name you typed while logging, if you tap Estimate Macros with AI when the food isn't in the on-device database
No personal identifiers (name, email, account info) are included in AI requests. A randomly generated device identifier is used by our proxy solely for rate limiting and is not forwarded to Google.
We use the paid Gemini API tier. Under Google's paid tier terms, Google does not use your prompts or responses to train or improve its products, and does not route them to human reviewers. Google retains requests only for a limited window to detect abuse of its service and for legal compliance. Google's full handling of this data is governed by the Gemini API Terms of Service.
6. Food Database
The App includes a bundled food database stored on your device for nutrition lookups. For barcode scans, the App may also query an external food database over the internet to retrieve additional nutrition information. In those cases, only the barcode is sent. No personal data, account information, or device identifiers are included in these requests.
The bundled food database is built from Open Food Facts data, © Open Food Facts contributors, available under the Open Database License.
7. Data Export
The App allows you to export your data as a backup file. Exported files are created temporarily on your device and shared only through the method you choose. We never receive or have access to your exported data.
8. Internet Permission
The App requires internet access for food database lookups, optional third-party AI features, and optional web search. All network connections use encrypted HTTPS. The App does not make any network requests in the background or when not in active use.
9. Analytics & Crash Reporting
The App does not collect analytics, advertising data, or crash reports. No usage data is transmitted.
10. Children's Privacy
The App is not directed at children under 13. We do not knowingly collect any information from children.
11. Changes to This Policy
We may update this policy from time to time. Any changes will be reflected on this page with an updated date. Continued use of the App after changes constitutes acceptance of the updated policy.
12. Contact
If you have any questions about this privacy policy, please contact us at: rexhep.rexhepi.5@gmail.com