Not for beginners
While this may have some use for more advanced learners to practice speaking, I don't think it's for beginners; it is just too much frustration.
Firstly, it constantly mishears what I say, claiming it heard something completely different.
Then the feedback is broken. Both audio and text stutters, breaks up, or ends abruptly. I know this is not due to my connection speed and has occurred over several days now. This isn't just an occasional issue; it is a major annoyance.
Perhaps this could be tolerated better if there seemed to be a clear and logical approach to learning, but there isn't. Even with the settings at absolute beginner, it asks you to translate words or phrases from your native language to the language you want to learn. Now, to me, absolute beginner means they know nothing, yet it's expecting them to provide translations?
Yes, with a little prompting it will supply the vocabulary, but it's not really effective teaching, to me.
Even that could be tolerated, to a degree, but this thing seems obsessed with trying to get you to ask for tea or coffee.
Now, I don't know about anyone else, but I'm sure my first words to someone in another language won't be asking for tea or coffee. Nor commenting about the size of their house, even if that's where I meet them.
You can ask it to change topic, and in fairness it does, for a while, but always reverts back.
It is undoubtedly clever, and if you already have a fair knowledge of the language I can see the benefit for speaking practice, but to learn a language, no, I think you're better off with a structured course from a professional, or if you can afford it, a tutor.
Could it supplement other teaching? Yes, potentially, but with one caveat: don't trust the pronunciation fully.
For total transparency, I tried the free version (10 minutes per day) and thought it had promise, so I paid for the subscription. Sadly, that's when these issues became apparent and I just got so frustrated and angry. Two days in and I have cancelled the subscription