Have
you read the above quote from the licence terms, Marco?

It seems clear. But, you might write to Paul Hemetsberger and ask him:
paul@dict.cc
By the way, the dict.cc
app for iOS is freely available:
https://itunes.apple.com/sk/app/dict...327732352?mt=8
So, you can already use it with Marvin today (just like the Lingvo app), provided we can determine the URL launch scheme for the dict.cc app. (Paul could help with that, too.)