Supported languages
The iK Health App is available in several languages:

English, French, Spanish.

If your Android or iOS device is set to one of the languages supported by the iK Health App, the iK Health App will also display in that language.

Unsupported languages
On Android devices
If your phone is set to one of the languages that the iK Health application does not support, the iK Health application will display in English.

On iOS devices
If you want to keep your phone’s default language in one of the unsupported languages, but want the iK Health app to display in one of the other supported languages (change the default English), set one of the other supported languages as the preferred language (second default language) in your phone’s settings, and the iK Health app will then display in that language.

This can be done under Phone settings > General > Language and region. There, tap Edit in the top right corner and on the next screen change the list of preferred languages by moving the languages up or down in the list.