1. Who operates MelonSpank
MelonSpank is developed and operated by the MelonSpank team. This privacy policy applies to the MelonSpank iOS application and the website at melonspank.com.
2. Data processed on-device only
The following data is captured and immediately processed on your iPhone. It is never transmitted to our servers or any third party.
- Microphone audio — a short recording of the tapping sound. The raw audio signal is discarded immediately after feature extraction. It is never stored to disk and never uploaded.
- DSP acoustic features — spectral coefficients, resonance frequency estimates, and decay characteristics derived from the raw audio. These numerical values are used locally to compute the Brix prediction and to generate the anonymized feature hash described below.
Your voice and ambient sounds are never recorded. The app requests microphone access solely to capture the mechanical tap impulse. No audio file is created, saved, or uploaded.
3. Data sent to our servers
When you submit a melon rating, the following fields are transmitted over HTTPS to our AWS backend. All fields are non-identifying by design.
- Anonymous UUID — a random identifier generated on first launch. It regenerates if you delete and reinstall the app. It is not linked to your Apple ID, name, or any identifier controlled by Apple.
- Coarse GPS coordinates (optional) — only collected if you grant location permission. Coordinates are rounded to approximately 100 m accuracy before transmission. Precise GPS is never stored or transmitted. You can decline with no loss of core functionality.
- Predicted Brix score — the sweetness estimate produced by the on-device model (for example, "12.4 °Bx").
- Star rating — a 0–5 star rating you submit after tasting, if you choose to submit one.
- Melon variety — the variety you selected (for example, "watermelon" or "charentais").
- Country/region setting — the region code from your device locale (for example, "FR" or "US"). Not derived from GPS.
- Feature hash — a SHA-256 hash of aggregate acoustic feature values. This one-way hash allows us to detect duplicate submissions without retaining any recoverable acoustic data.
- Model version — the version of the on-device ML model that produced the prediction.
- App version — the installed version of MelonSpank.
- Device model — the hardware model string (for example, "iPhone14,5"), used to normalize predictions across device microphone characteristics.
- Timestamp — UTC timestamp of the submission.
None of the fields above, individually or in combination, are capable of identifying you as a natural person.
4. Why we collect it
MelonSpank is free during its beta period. In exchange, we ask users to contribute anonymous acoustic measurements and ratings so we can improve the community machine learning model.
Specifically, we use the submitted data to:
- Retrain and refine the on-device Brix prediction model on a continuous basis.
- Calibrate model accuracy by region and melon variety.
- Detect and filter anomalous or low-quality submissions using the device model and feature hash.
- Understand which varieties and regions need more training data.
We do not use your data for advertising, profiling, or any purpose unrelated to improving the melon-sweetness prediction model.
5. Data we never collect
| Data type |
Status |
| Name, email address, phone number | Never |
| Photos or camera access | Never |
| Address book or contacts | Never |
| Precise GPS location | Never |
| Raw audio recordings | Never |
| Health or fitness data | Never |
| Payment or financial information | Never |
| Advertising identifier (IDFA) | Never |
| Apple ID or iCloud data | Never |
| Browsing history or cross-app tracking | Never |
6. Data retention
- Individual rating records — kept for 90 days, then automatically expired via a DynamoDB TTL attribute and permanently deleted.
- Aggregated regional statistics — statistical summaries (mean Brix by region, variety, and device model) derived from raw records are kept indefinitely for model-training purposes. These aggregates contain no per-submission identifiers.
7. Third parties
We use Amazon Web Services (AWS), region eu-west-1 (Ireland), to host our backend infrastructure. AWS acts as a data processor under our instructions and is bound by the AWS data processing addendum.
We do not share, sell, rent, or disclose your data to any other third party. There are no advertising networks, analytics SDKs, or social-media integrations in the app. We do not use Firebase, Google Analytics, Facebook SDK, Amplitude, Mixpanel, or any equivalent service.
8. Your rights (GDPR / CCPA)
Under the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA), you have the following rights regarding your data:
- Right to access — you may request a copy of any data associated with your anonymous device UUID.
- Right to deletion — you may request deletion of all records linked to your device UUID. To do so, open a support ticket with your UUID (visible in the app under Settings). We will delete all associated rows within 30 days.
- Right to correction — if you believe a submission was made in error, open a support ticket and we will remove it.
- Right to portability — you may request an export of data associated with your device UUID in JSON format.
- Right to opt out of data sales (CCPA) — we do not sell data. There is nothing to opt out of.
To exercise any of these rights, open a support ticket and select the "Privacy" category. We will respond within 30 days.
9. Children
MelonSpank is rated 4+ on the Apple App Store and is suitable for all ages. We do not knowingly collect personal information from any user. Because none of the data we collect is capable of identifying an individual, it follows that we cannot knowingly collect identifying data from anyone under the age of 13.
If you are a parent or guardian and believe identifying data relating to your child has been inadvertently collected, please open a support ticket and we will take immediate steps to delete it.
10. Security
- All data transmissions use HTTPS with TLS 1.3.
- Data at rest is encrypted using AWS DynamoDB encryption at rest (AES-256, AWS-managed keys) and Amazon S3 server-side encryption (SSE-S3).
- Access to production infrastructure is restricted to authorized personnel via IAM roles with least-privilege policies.
11. Changes to this policy
If we materially update this privacy policy, we will update the effective date at the top of this page. For significant changes affecting data use, we will display an in-app notice on first launch after the update. Continued use of the app after that constitutes acceptance of the revised policy.
The current version is always available at melonspank.com/privacy.
