Yeah, unless I am completely off in my estimation of current technology, this program can probably narrow common plants down to genus and maybe sometimes species but I wouldn't expect it to be accurate when it comes to a species with a lot of morphological diversity.
Also, now that im thinking about it, for a program like this to be accurate, it would need to instruct you to take multiple pictures of specific parts of the plant. Even experts can have a hard time identifying a plant from the wrong angle.
Thirdly, the reviews talk about a free trial being offered but cancelling requires you to backflip through several flaming hoops so that immediately makes me suspicious.