The Chipolo app is available in a few different languages:
Slovenian, English, German, Dutch, French, Italian, Spanish, Japanese, Swedish, Finnish, Norwegian (Bokmål), Russian, Chinese, Turkish and Czech.
If your Android or iOS device is set to one of the languages the Chipolo app supports, the Chipolo app will also display in that language.
On Andriod devices
If your phone is set to one of the languages the Chipolo app doesn't support, the Chipolo app will display in English instead.
On iOS devices
If you would like to keep your phone's default language in one of the unsupported languages, but want the Chipolo app to display in one of the other supported languages (change it from the default English), set up one of the other supported languages as the preferred (second default) language in your phone settings, and the Chipolo app will then display in that language instead.
This can be done in Phone settings > General > Language and region. In there, tap Edit in the top right corner and on the next screen change the Preferred language list by moving the languages up or down the list.