I have changed the language settings, but displayed language is not changed.

A903 The language settings of Socialife are based on following specification.

1) User interface such as menu, buttons, dialogs of the app is in the language of Android OS or Windows OS settings of your device.
As long as you do not change the OS settings, the language will be kept.
2) Information window of Socialife which appears automatically or can be shown from [Information] menu is basically in the language you have selected when you initially agreed to Terms of Use and Privacy Policy of Socialife.
For some countries and languages, we deliver the information in English. As long as you do not sign out from Socialife, the language will be kept.
3) If you change "Language/region for recommended feeds" from the setting menu, the recommended feeds within "Add feeds" or "Discovery " section will be localized feeds.
(Some feeds might be in English even in a region which other language is spoken)

1) and 3) have individual settings by each device even though you sign in with your same "Sign-in ID" to Socialife.
2) is always the same even when using the app with different devices, unless you sign out from Socialife and change the language by agreement with the different device's Terms of Use and Privacy Policy.