[tassl]

From the technological point of view I can just say wow! Congratulations, this is a great app.

Aside from that, and as a Spanish native speaker, the translated text sounds really weird to me. Even without knowing English I would be able to understand the translated text (at least the example that you gave) but it can be improved. But this is the only con that I see to your application. Probably you're already working on that, but I thought that you might like this input.

Great idea!!