I’m sticking my toe into Android Development
Here are some reference links
What version of Android should you develop for? Many say develop to the oldest version that you can in order to support the biggest market share. However the older versions are only in a small % of the phones. The newest versions of Android are not supported in many phones yet. The sweet spot in my opinion starts at 10% coverage which today is 2.1. Visit this site for the latest stats.