Last updated: 28 July 2026
Ellingham is an offline interactive Ellingham diagram and reaction calculator. It computes standard enthalpy, entropy, Gibbs free energy and the equilibrium constant for oxide, carbon and hydrogen reactions from the NIST-JANAF Shomate coefficients, entirely on your device. It has no account and no server. This policy explains, plainly, what that means.
Ellingham stores exactly one thing: whether you prefer kelvin or Celsius for temperature. That single display preference lives in the app's private storage on your device so the app remembers it next time you open it. Nothing else is written anywhere.
The temperature you set, the reactions you select, and the crossovers you look at are held in memory only while you are using the screen. They are not saved to disk, not kept in a history, and not sent anywhere. Close the app and they are gone.
Most apps that promise privacy still ship with the ability to reach the internet and simply choose not to use it. Ellingham does not have that ability. The release build declares no INTERNET permission, which means Android itself will refuse any network request the app might make. You can verify this on the app's Play Store listing, where the permissions section will show none, or with any APK inspection tool.
Every Shomate coefficient, every species range, every equation and every citation is bundled inside the app. Nothing is fetched, and there is nothing to fetch.
The About screen lists the two sibling apps in the MetKit suite, HeatTreat and HEA, and tapping one opens its Google Play listing. This is worth being precise about, because it is the only thing in the app that points outward.
Tapping one of those rows hands a Play Store web address to Android, which opens it in the Play Store app or your browser. Ellingham itself makes no network request and could not make one; it passes the address along and takes no further part. The address contains only the sibling app's package name. It carries no identifier for you or your device, no referrer, and nothing about what you have done in the app. Ellingham is not told whether you went on to install anything, and receives no attribution, referral, or affiliate data of any kind. Once the Play Store or your browser opens, that app's own privacy policy governs what happens next.
Ellingham does not collect names, email addresses, contacts, location, photos, device identifiers, usage analytics, crash reports, or any other personal information. It does not know which reactions you looked at, what temperature you set, or that you opened it at all. There is no mechanism by which it could report any of this.
Ellingham requests no runtime permissions. It does not ask for camera, photos, storage, microphone, location, contacts, or notifications. The only entry in its manifest is an Android system permission that the app defines for itself, which grants no access to your device or your data and is added automatically by the Android support libraries.
Ellingham gives standard-state screening estimates for education and orientation. They assume pure condensed phases at unit activity and a total pressure of 1 bar, and they ignore solution behaviour, so they are not activity-corrected results and not a substitute for measured data. It is not a certification tool and does not issue specifications. Every quantity in the app shows its equation, its NIST source, and the temperature range that source covers, and a reaction is withheld outright, with the limiting species named, when the requested temperature falls outside that range. Confirm against the applicable data before relying on a number.
The thermochemical data are the NIST-JANAF Thermochemical Tables (M. W. Chase Jr., NIST-JANAF Thermochemical Tables, Fourth Edition, Journal of Physical and Chemical Reference Data, Monograph 9, 1998), obtained through the NIST Chemistry WebBook. As a work of the United States Government these are in the public domain. Each species carries its WebBook identifier and its tabulated temperature range inside the app. They contain no personal data. Including them involves no data collection from you and no network access.
Ellingham does not knowingly collect any data from anyone, including children. There is nothing to collect.
If this policy ever changes, the updated version will be posted at this same address with a new date above. Any change that would affect data handling would be described here before it took effect.
Questions about this policy can be sent to contact@futigo.io.