Fantastic how easy ist is to add Text to Speech to your app! And how good the voices sound!
In my apps for language learning I use French, Spanish, German and English voices and they all sound great. Luckily it seems as the users don’t have any problems installing the voice data. It’s done automatically if you just once have Internet connection a short while.
Being an old language teacher I’m impressed how efficient apps can be for language learning today.
Here you can see a video about how Carmen teaches you Spanish:
Link to app: https://play.google.com/store/apps/details?id=talkensp.demo
Or how Michelle teaches you French.
Link to app: https://play.google.com/store/apps/details?id=talkenfr.demo