Your camera, your microphone and what you capture stay on your iPhone. What the app does send is listed here, all of it.
Last updated 4 October 2026
In short. Thermal FX never uploads camera frames, audio, photos or videos. It has no account and no advertising, does not track you across other companies' apps or websites, and sells nothing about you. It sends usage statistics — which features are used, whether a purchase went through — to our analytics provider, Amplitude, with no name, email or Apple Account attached. At launch it also downloads a small settings file from this site.
Thermal FX reads the live camera image, re-colours it on your device's GPU and draws the result on screen. To place the X-ray bones it looks for a person, a hand or a face in the image, using Apple's on-device frameworks. Frames exist in memory for as long as they are on screen and are then discarded. They are never written to disk unless you tap the shutter, and never leave the device.
Ghost mode reads the microphone's sound level to move its meter, and video recordings include an audio track. Both are processed on the device. Nothing is recorded unless you start a video recording, and no audio is transmitted.
The app asks for add-only access, which is the narrowest permission iOS offers. It can write the photos and videos you capture to your library and cannot read, browse or delete anything that is already there.
Captures are stored inside the app's own storage on your device, and in your photo library if you allowed that. They belong to you. Deleting the app removes the copies held inside it.
To learn which parts of the app people use and whether purchases work, the App Store version of Thermal FX sends usage events to Amplitude, an analytics service, on servers in the United States. An event says that something happened in the app, for example:
Each event also carries whether you have Thermal FX Pro and the app version, and Amplitude's software adds a few details about the device: an identifier Apple gives the app for your iPhone (the identifier for vendor), the iOS version and the device's language. Like any internet request, the event reaches Amplitude from your IP address; Amplitude keeps it and uses it to estimate the country, region and city the event came from.
What the statistics never contain: your name, email address or Apple Account; photos, videos, camera frames or audio; your precise location; contacts or anything else from your device; and the advertising identifier, which the app does not read. Nothing in them tells us who you are, and we do not combine them with any other information to find out. They are not used for advertising and are not sold or shared with anyone else. There is no switch in the app to turn them off; deleting the app stops them.
At launch the app downloads config.json from this site,
thermal.slumbiapp.com — how long the free trials run, and similar settings. It is
a plain download: the app sends nothing in it. As with opening any web page, the
request reaches the site's hosting provider, Cloudflare, from your IP address.
Thermal FX Pro is sold through Apple's In-App Purchase system. Apple handles the payment; the app is only told whether an entitlement is active. Your name, payment details and Apple Account are never visible to the app or to us. Apple's handling of that transaction is covered by Apple's privacy policy.
A code typed into the app to unlock Pro is checked on your iPhone and is not sent anywhere; the statistics record only that a code was accepted.
Thermal FX is rated 4+. We do not knowingly collect personal information from children. The usage statistics above are collected the same way for everyone and are not linked to a person.
Laws such as the GDPR and the CCPA give you rights to access, correct, export or delete the personal data a company holds about you. The usage statistics are the only data we hold, and they carry no name or contact details, so we cannot look them up by who you are; if you have a question or a request about them, write to us and we will help as far as we are able. If you want the app's local captures gone, delete them in the app's gallery or delete the app.
If this policy changes, the revised version will be posted here with a new date at the top. Until 4 October 2026 this page said the app sent nothing at all; that stopped being true when usage statistics and the settings file were added, and this version says what is sent.
Questions about this policy: support@thermal.slumbiapp.com.