This was my original question:
I want to be able to open a pdf file in my app using the android\'s built in pdf viewer app, but i dont know how to
I was also faced same issue when was trying to display PDF on android device and finally end up with the solution (3rd party PDF library integration)
https://github.com/JoanZapata/android-pdfview
while I have tested multiple libraries for this listed below which are also working,
https://github.com/jblough/Android-Pdf-Viewer-Library
& mupdf which comes with the ndk flavour (https://code.google.com/p/mupdf/downloads/detail?name=mupdf-1.2-source.zip&can=2&q=) and need to extract with NDK and then use it in application as a jar or java etc. nice article to explain the use of this library @ http://dixitpatel.com/integrating-pdf-in-android-application/