You can now access your accounts in other languages using the same game app. This means that with each language you'd like to play in, you need to attach a different email address and password, so that you can access it again when you’d like to switch languages.
To do this, make sure to setup an email and password on the account you are currently using, and again when start playing in a different language.
To switch to an account in another language, go to "Menu" and tap "Log out". Then select the the language you want and enter the new email and password associated with that particular account.