Here is some development information about the new app I created called Slim BMI Calculator.
Most of the process of creating this app was pretty straight forward as you would expect. I used the Android SDK from here, which is has everything you need, including an Eclipse IDE with Android Development Tools plugin already installed, and the Android emulator.
As for the code, it's pretty straight forward, I was using activities and views which used layouts outlined in XML files. The strings, including HTML content for the documentation / about views, were stored in XML bundles which allow to localize your app in other languages as well. The user provided input is stored in an SQLite database.
The only novel thing would be the use of a charting library called aFreeChart, which is a Android port of the famous Java library called jFreeChart. This library allows you to create various types of charts with customizable content.
Here are some screenshots of the application running on a Samsung Galaxy SII with Android 4.0.3 and on an Emulator with Android 2.3.3 with Romanian locale:
Samsung Galaxy SII: