There a good news:
It works! We can do annotations now!
I'm not quite finished with it yet, but you can see already a small video of my first prototype version
here (apologies for the bad quality).
There are still a few quirks and glitches, which have to be removed before I can upload it. But at the moment it looks very promising.
It is actually quite a bit of hard work to do the reverse engineering. With no official SDK and no documentation... (I guess I should add a donation button, shouldn't I? .. just kidding
)
Am I right to assume that there is a general interest in this unofficial upgrade to your readers?