The short version: your readings never leave your phone.
What stays on your phone
The camera feed. KelvinCam asks for Camera access so it can read live pixel data and estimate color temperature, brightness and exposure. The feed is processed in real time on your device. It is never recorded or sent anywhere.
Saved readings. When you save a reading, KelvinCam keeps it inside the app: the measurements, your camera settings, any notes you add, and a small preview image of the frame. It is shared only with KelvinCam's own widgets on the same device. Like any app's data, it can be included in your device backups (for example iCloud Backup). Deleting a reading, or the app, removes it.
The lighting assistant. The assistant runs on Apple's on-device model. Your questions and its answers stay on your phone.
Sharing and export. Readings leave your phone only when you share or export them yourself, and they go only where you send them.
Payments. Apple handles the KelvinCam Pro purchase. We never see your name, Apple Account or payment details.
What KelvinCam sends, and why
KelvinCam sends two kinds of data. Neither is linked to your identity: the app has no account, never asks who you are, and doesn't use Apple's advertising identifier (IDFA). Both use random IDs that the app creates itself, and deleting the app deletes them.
1. Anonymous usage analytics. So we can see which features help and where people get stuck, the app sends:
- Which screens you open, such as the meter, Guides, History or the Pro page.
- A short, fixed list of events: the app was opened, closed, installed or updated; a reading was saved (photo or video mode only, never the reading itself); the Pro page was shown; a Pro preview was started or used; Buy was tapped; a Pro purchase was started from the App Store; Pro was unlocked.
- When a spot on the screen is tapped rapidly several times (a sign something isn't responding): which screen it was on, where on the screen, and the type of control, never its text.
- Basic device details: device type and model, iOS and app version, language and region setting, time zone, screen size, and whether you're on Wi-Fi or cellular.
- A random ID the app creates, so several visits from one phone count as one user.
This goes to our analytics provider, PostHog, on its US cloud. PostHog uses your IP address to estimate your country or region, then discards the address; city-level location is removed. KelvinCam itself never reads your location. Version 1.6 of the app sends the same data to HeyCatch, our previous provider, until we close that account; updating to the latest version switches to PostHog.
2. Install and purchase measurement. So we know which ads and search keywords lead to people buying Pro, the app sends these to a small server we run on Cloudflare:
- A random install ID the app creates on first launch.
- An attribution token from Apple's AdServices framework. Our server passes it to Apple, which replies only with whether the install came from an Apple Ads campaign and, if it did, which campaign, ad group, keyword and country. We delete the token once Apple has answered.
- When you unlock Pro: the App Store transaction ID, the product and the purchase date. No name, email or payment details.
- The same Pro page and purchase events listed above.
Our server does not store your IP address.
What is never sent
- Your light readings: Kelvin, EV, lux or exposure values.
- Camera images, preview images or video.
- Your notes, or anything else you type.
- Your name, email, Apple Account, contacts or precise location.
Who receives it
- PostHog, Inc. (United States) provides the usage analytics and processes it only on our behalf. See PostHog's privacy policy.
- HeyCatch, Inc. (United States), our previous analytics provider, receives the same usage analytics from version 1.6 of the app until we close that account. See HeyCatch's privacy policy.
- Cloudflare, Inc. hosts our measurement server and this website.
- Apple answers the Apple Ads attribution request and handles every purchase.
Nobody else. We don't sell data, share it for advertising, or combine it with data from other companies.
Tracking
KelvinCam has no ads and doesn't track you across other companies' apps or websites. It doesn't use the advertising identifier (IDFA), which is why it never asks for tracking permission.
How long we keep it
On the PostHog plan we use, usage analytics stay available to us for one year, and older events drop out of our reports. PostHog doesn't promise to erase them at that point, so they may remain in its storage, still not linked to you. Usage analytics sent to HeyCatch are deleted or anonymized within two months after we close that account. Install and purchase records on our own server are kept for up to two years, then deleted.
Your choices
Because none of this is tied to your name or account, we usually can't tell which records are yours. Deleting KelvinCam erases its random IDs, so nothing sent after a reinstall can be connected to what came before. If you'd like us to look for and delete data anyway, or you have a question about your privacy rights where you live (for example under GDPR or California law), email us and we'll help.
About this website
rivotlabs.com is a static site hosted on Cloudflare Pages. It runs no JavaScript (blocked by our own Content-Security-Policy), sets no cookies, and includes no analytics. The only third-party resource loaded is Google Fonts, which may log standard request metadata (IP address, user agent) per Google's Fonts privacy notice. We don't see or store any of it.
Children
KelvinCam is not directed at children under 13, and we don't knowingly collect personal information from children.
Changes
When what KelvinCam collects changes, we update this page and the date at the top. An earlier version of this page said KelvinCam sent no data at all. That stopped being true with version 1.4 (July 2026), which added install and purchase measurement, and with version 1.6 (October 2026), which added usage analytics. We should have updated this page then, and we're sorry we didn't. Version 1.6.1 (October 2026) moved usage analytics from HeyCatch to PostHog and started reporting rapid repeated taps, as described above. Past versions are available on request.
Contact
Questions, concerns, or requests about your data: support@rivotlabs.com. We answer every email personally.
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