This example will ask you a number for defining N x N Queen problem.
Basically, Android includes Linux kernel as operating system, libraries ( C language), Android runtime ( Dalvik virtual machine for Java byte code), and application framework (APIs for Java) . The applications we wanna develop are based on this application framework and Java 1.5 language specification, and will run on Android runtime.
Until now, Google only has prototype cell phone for running Android platform. Due to this reason, all the applications need to execute on the emulator which emulates the same environment just like you really have the hardware. There is a simple example that can give an idea about developing a Android application.
Then it will calculate the possibility of results showing as a simple checker.
P.S: It runs on the Android emulator.