With the language detection enabled langify will detect your users prefered language and adjust accordingly. Please make sure that you've assigned the correct language codes to your languages as described here.
Enable the language detection
Click "Enable" next to "Language Detection is disabled" in the "Settings / Language Switcher" section (http://langify-app.com/language-switcher) to enable the language detection.
You can disable the language detection again by clicking "Disable" next to "Language Detection is enabled".
Good luck!
We hope this tutorial was of use, if you are still struggling with your translations or have encountered any problems which we haven't discussed here feel free to contact us.