First, in the section "Expressions are flashcards on steroids", the flavor text on each element (Translations, Audio, etc) is identical.
Next, I look at the pricing and get one idea. Then when I create an account and go to upgrade, I see completely different pricing options. Its not that I care so much about the options, but it kind of worries me!
At one point I swear I saw the phrase "Say something about comprehensible input" instead of an explanation of CI, and the sentence itself was duplicated but now I don't. Maybe you are making this landing page live? It _is_ a nice landing page, to be sure.
Overall, I think it looks really cool and I'm interested in trying it out but just a little nervous at the moment.