Hi Greebgnev,
I believe the site with in-document translations that you are looking for is Conradish.net. I haven't heard of any other sites that have this feature. I am assuming you already know about Google/Chrome translate.
Our application currently doesn't display aspect pairs, but it does provide information about verb conjugation (and inflections of other word types).
A picture is worth a thousand words:
2011.06.30-word_reference_popup-2.jpg
Best regards,
Vladyslav Mukherjee