This is an Android application that allows exploration of the available system Java libraries, using Java's reflection capabilities.
You would think this wouldn't be that useful, given that the Android documentation describes the classes available for developers to use.
However...
It turns out that Android ships with various other Java libraries, which are not advertised and aren't officially supported.
It also turns out that the Dalvik classloader will prefer these system-installed libraries to any versions of the same libraries that come as part of an application's APK file.
So it's useful to discover what libraries are present in the Android system, waiting like a depth charge to sabotage your app...
Note: The app includes wrappers for
java.lang.Package
information, but this doesn't appear to work – Package.getPackages() returns nothing, and
Package.getPackage(name) always returns a Package object with no information in it, even for non-existent
package names.