ItchLog (“the App”, “we”, “us”) is developed by an individual developer (Min Hwang, “the Developer”). This Privacy Policy explains what information ItchLog collects, how it is used, and what choices you have.
ItchLog is a symptom logger. It does not diagnose, treat, or give medical advice. Based on your logs, the App shows simple on-device statistics (observed relationships between food/lifestyle factors and changes in your symptoms). These calculations run only on your device, are never sent anywhere, and are not a diagnosis or a determination of cause.
Contact: smhwang0715@gmail.com
1. Information We Collect
a. Account Information
When you create an account, we collect an email address and password, or, if you sign in with Apple or Google, the identifier and email address those services provide (Apple lets you hide your real email via “Hide My Email”). Passwords are handled by Firebase Authentication, and the Developer cannot see them. Your email address is also stored in your user profile document in Firestore. The App does not collect or store your name or a nickname (when you sign in with Google, the name Google provides may remain in the Firebase Authentication record, but the App does not use it). This information is used solely to identify your account and sync your data across devices.
b. Health & Fitness Data (Apple HealthKit)
If you grant permission, ItchLog reads sleep duration, workouts (type and duration), and step count from the Health app. This data is used only to show in that day’s summary and, when a sweaty workout is found, to pre-check the “Sweat & workout” item; it is stored in Firestore as a per-day health record. ItchLog does not write any data to the Health app. You can revoke HealthKit access at any time in iOS Settings → Privacy & Security → Health → ItchLog.
c. Location & Weather Data
If you grant location permission, ItchLog uses your device’s location to fetch local temperature, humidity, UV index, and air quality index for the current day. Temperature, humidity, and UV index come from Apple WeatherKit, an Apple service, which receives your device’s location as is. Air quality comes from the Open-Meteo Air Quality API, which receives only approximate coordinates rounded to two decimal places (about 1 km). We do not store your location itself; only the resulting weather/AQI values are saved as part of your daily environment log. You can revoke location access at any time in iOS Settings → Privacy & Security → Location Services → ItchLog.
d. Photos
You may choose to attach photos of a specific body-map mark (e.g. to document a flare-up). You can pick a photo from your photo library or take one with the camera inside the App. Before upload, each photo is downscaled to a JPEG whose longer side is 1600 pixels, then uploaded to Firebase Storage, linked to that specific log entry. A copy is also cached on your device so photos load quickly; this cache is cleared when you sign out or delete your account. Photos are only ever uploaded when you actively choose to attach one.
e. Symptom & Lifestyle Logs You Enter
This is the core data of the App, which you log yourself:
- Body-map marks: location and one of three severity levels (mild, moderate, severe)
- Meals: time and food names for each meal
- Condition: sweat & workout, and gut condition (any of loose stool/diarrhea, constipation, bloating/gas, stomach pain, heartburn/reflux, nausea, or “same as usual”)
- Products & routine: moisturizing, hot showers, new cosmetics/skincare products (name, start date), and laundry detergent changes (optional name, start date)
- Medication use: whether a steroid (topical or oral) or another medication (e.g. an antihistamine) was used that day, and optionally which body-map marks the steroid went on. Medication names and doses are not collected.
- Environmental exposures: secondhand smoke, pollen, pets, alcohol, dust, wool/synthetic fabric contact, travel/nights away
f. Subscription & Payment Information
ItchLog offers an optional paid subscription, processed entirely through Apple’s StoreKit / App Store billing. We never receive or store your payment card details — Apple handles the transaction and only informs the App of your subscription status (whether it is active, and the monthly or yearly plan). This subscription status is stored in your user profile document in Firestore.
g. What We Do NOT Collect
ItchLog does not use any analytics SDK, advertising SDK, or cross-app/cross-site tracking. We deliberately do not include Firebase Analytics or any similar tool.
The optional once-a-day log reminder you can turn on in Settings is a local notification scheduled only on your device; no data is sent anywhere for it.
2. How We Use Your Information
We use the information above only to:
- Operate your account and sync your logs across your devices (Firebase Authentication, Firestore, Storage)
- Pre-fill parts of your daily log with your Health/weather/AQI data, purely for your convenience
- Display your own body map, history, and photos back to you within the App
- Process your subscription status via Apple
- Respond to support requests you send us
We do not use your data for advertising, and we do not sell your data to anyone.
3. Data Storage & Security
Your data is stored using Firebase (Firestore database, Firebase Authentication, and Firebase Storage), a service operated by Google. Firebase infrastructure may store and process data on servers located outside your country of residence, including in the United States. Data in transit is encrypted (HTTPS/TLS). Access to your data is protected by Firebase security rules scoped to your authenticated account, so only you can read or write your own records.
Infrastructure Logs & Administrator Access
Independently of any analytics SDK (ItchLog uses none — see Section 1g), Firebase/Google infrastructure automatically logs certain technical metadata for every request, such as your IP address, request timestamp, and sign-in method, for security, abuse-prevention, and billing purposes. This is standard infrastructure logging, not behavioral tracking, and we cannot disable it. In addition, as the App’s administrator, the Developer has the technical ability to view raw records stored in Firestore/Storage (e.g. via the Firebase Console) for support, debugging, and service-operation purposes; this access is not used to profile or analyze individual users’ behavior.
4. Third-Party Services We Use
| Service | Purpose | Data involved |
|---|---|---|
| Firebase Authentication (Google) | Account sign-in | Email, Apple/Google identifier |
| Firebase Firestore (Google) | Storing your logs | All logs described in Section 1 |
| Firebase Storage (Google) | Storing your photos | Photos you attach |
| Apple HealthKit | Sleep/workout/step auto-logging | Sleep duration, workouts (type and duration), step count |
| Apple WeatherKit | Weather/UV auto-logging | Device location, weather data |
| Open-Meteo Air Quality API | Air quality index | Approximate coordinates rounded to two decimal places only, no account identifiers |
| Sign in with Apple / Google Sign-In | Account authentication | Email, account identifier |
| Apple StoreKit / App Store | Subscription billing | Handled entirely by Apple |
Each of these providers has its own privacy policy governing how they handle data on our behalf.
5. Data Retention
We retain your data for as long as your account remains active. You can delete your account yourself in the App under Settings > Delete Account; your associated logs, photos, and profile data are deleted from our systems immediately, except where we are required to retain certain records to comply with legal obligations (e.g. transaction records for subscriptions, which are retained by Apple per its own policies).
6. Your Rights & Choices
You may, at any time:
- Access, edit, or delete individual logs directly within the App
- Revoke HealthKit or Location permissions via iOS Settings
- Delete your entire account directly in the App under Settings > Delete Account (takes effect immediately)
- Request a copy of your data by emailing smhwang0715@gmail.com
We will respond to and process such requests within a reasonable time, generally within 30 days.
7. Children’s Privacy
ItchLog is not directed at children, and we do not knowingly collect personal information from children under 14. If you believe a child has provided us with personal information, please contact us and we will delete it.
8. Our Commitment on Health Data
In line with Apple’s HealthKit guidelines, ItchLog:
- Does not use HealthKit data for advertising or marketing purposes
- Does not sell HealthKit data, or share it with data brokers or advertising platforms
- Uses HealthKit data solely to provide the health-tracking features described in this policy
9. Changes to This Policy
We may update this Privacy Policy from time to time. If we make material changes, we will update the “Last updated” date above and, where appropriate, notify you within the App.
10. Contact Us
If you have any questions about this Privacy Policy or your data, contact:
Min Hwang Email: smhwang0715@gmail.com