I'm a teacher in a polyglot school where we teach French, English, Spanish, Portuguese and Chinese. I've created an application that allows teachers to provide individual support to beginners. It uses the text-to-spech module. I was able to configure one instance of text-to-spech in French, one in Spanish and one in English. However, I was unable to create an instance in Portuguese or Chinese.
Although I know that in Portuguese it's possible.
But in this example, it works because it's the default language...
I hadn't paid much attention to the only languages available in the drop-down list, as it seemed obvious to me that MIT APP Inventor was going to use the artificial voice modules present on the phone anyway.