My perfect language learning mobile app

Over the last few months I've been searching around for language learning programs for mobile phones and found very few of any substance, which is odd really given that phones are perfect tools for language learning. There are plenty of dictionaries and thesauruses available, one or two phrasebook programs and a few gap-fill/exercise-type programs.

It feels a bit like computer language learning programs five or six years ago, when they were stuck simply replicating the kinds of exercises you can find in textbooks. Now, developers have really begun to work out how to exploit the multimedia and interactive qualities of computers to offer things that books can't. Something like English Central is a good example of how far online English language learning has come.

On a mobile phone developers really need to exploit the always-on, productive and mobile features of phones to allow people to organise their language learning. They need to take advantage of the phone's camera and the ability to be permanently connected to the internet.

What I would like to see is an app that could:

Take a picture of a menu/poster on the street and then offer an immediate translation. This would be like the app shown here

Be able to offer immediate defintitions from a variety of online dictionaries in the same way that dictionary.com does.

Be able to offer a variety of examples from corpora such as the British National Corpus. Also helpful to offer info about the frequency and usefulness of the words.

The ability to create your own list of vocabulary based on all of the above and to group them by topic or any other heading.

Basic things I think, but I haven't seen any app out there offering something like this. It would truly make ESL mobile for the learner.