Hi!
There are two bugs related to the "read in" feature both on the Wikipedia app than on the Wikipedia Beta app for Android.
1) even in my language is -e.g.- English if I am reading an article in Italian and I use the search feature I would expect to be searching on it.wp and not on en.wp (I told about this to the dev's at Wikimania, this is just a remind :)
2) if my language is English but I'm reading an article in Italian and I use the share feature I will be sharing the en.wp article instead of the it.wp one, as it should be. (I don't know if this bug is already known)
Thanks,
Jaqen