I am admittedly not experienced in developing for android. I am looking for some API that lets me browse the users files, without installing a separate app via intents. Right now I have found the
OI File Manager
This is a late answer but I worked on creating an android file explorer recently. https://github.com/mburman/Android-File-Explore
Its really straightforward. Essentially its just 1 file that you would need to integrate into your application - doesn't use intents either.