Is it possible to have an option in app to change the language, like on some websites there is a drop down menu and you can choose which language the content appears in?
Currently not possible. Please upvote this feature request and you will be notified when the status of this changes: Support for Multiple Languages | Voters | Adalo
If you only expect a couple languages and your app isn’t too complex, you could set up multiple versions of each screen and have the user directed to the screen with their language. However if your app is complex, this would be pretty difficult.