This question seems quite borderline with on-topic and off-topic. The reason this question us up is because of Flimzy's comment on the question:
I'm really not sure if this is about language learning. What do others think?
That really is the question. Are these types of questions allowable or not? To be clear on what type of questions are under question here, those questions should be about the machines that assist with learning a language. For example, rather than asking what is effective for improving fluency, the question would be about the books that assist in improving fluency.