What do you think about quality of English pronunciation in flash cards?

It is exactly the same as in google. Native speakers how good is it?

It is not 100% natural, but close enough for learning, in my opinion.

I tend to agree with dooo, it is definitely unnatural but I think the mechanic voice gives a good enough idea of how to pronounce the words. This, coupled with the audio from the lesson, should allow learners to achieve the proper pronunciation.