any pdf reader with annotation feature (open source)? I am looking for a pdf reader for android which can also  annotate, select, highlight text. Any open source option? 

Like Foxit Reader?
Adobe Reader X for Android v10.3 now supports annotation, highlights and commenting. It is not open source, but it is free to the end user.

There are currently no open source Android PDF utilities that have worthwhile annotation features. This wiki page at the University of Massachusetts Boston lists several open source android PDF viewers, with links: http://howto.wikispaces.umb.edu/PDF+Annotation+with+Android

(I can't post a reply containing more than two links, my apologies.)