No, 3 To 9 is not free (it costs 29000.00), and it also contains in-app purchases.
Not enough reviews to make a reliable assessment. The app needs more user feedback.
3 To 9 costs 29000.00 to download (and they also have additional in-app purchases).
To get estimated revenue of 3 To 9 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.