I'm just writing a quick post to link to this six part series I wrote on the AutoCAD DevBlog about porting a simple C# AutoCAD .NET plug-in to a Java Android app.
Here are the links:
Part 0 - VB.NET vs C#.
Part 1 - The C# AutoCAD plug-in.
Part 2 - Creating an Android project and porting our first C# to Java.
Part 3 - More C# to Java porting.
Part 4 - Adding a basic Android UI.
Part 5 - Using an Intent to launch a new Activity.
Part 6 - Download link for the finished app and summary.