Netbeans
This is a subject that's seldom talked about, but can be quite important. The NDK basically allows you to port any native C/C++ code/libraries into your Android project, using JNI (Java Native Interface).
I'm going to go through a quick and simple example of how you can display "Hello World" in your Android application using some native C.
A very annoying issue that I've noticed with the NBAndroid Netbeans plugin, is that it doesn't know how to properly attach an external JAR file to an Android Project.
If you right-click on libraries (under your project folder), and click on 'Add JAR/Folder', it will add a reference to that library/JAR file, which it will recognize in the code (detect all the classes, etc). The problem lies when you try to compile the project - at that point, it doesn't actually add the JAR to the project, which in turn gives you errors when running.