The app is really scammy. Sometimes translations are correct, or acceptable for the language, but are counted incorrectly if they don't match duolingo's translation. Which means you lose hearts which you have to buy to continue. It also will count minor typos as incorrect even though it is capable of recognizing your intent. If it doesn't register your speech, it will count against you too, even something as simple as the word "dos." All to push you to buy hearts. Nice concept but super scammy.