I am looking for a pdf reader for android which can also annotate, select, highlight text. Any open source option?
Like Foxit Reader?
I'm using ezPDF Reader, and it has the features you need.
But I don't know what you mean by Open Source. Maybe FREE? If yes, ezPDF Reader has a paid and a somewhat reduced (but not free) lite version.
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.)
I don't know of an opensource pdf editor (and i don't know if you can find one with many features), but Xodo is a great free (but not opensource) pdf editor. I even like it more than ezPDF. A while ago (2016/2017), I searched many pdf apps and xodo was the best one in my opinion.