You can switch languages by opening the app and going to the main menu. You will see the menu option "BIBLE" so tap that and you are taken to the language list. After it loads the list, you can scroll through and select the languages of your choice. Some languages have more than one version available. The green dots underneath each version name shows you if the text and audio is available for that translation.
Should you need further assistance or have a question, you're welcome to contact our Bible.is support team.