aSyncTaskDemo is an example using the aSyncTask class instead of threads. It counts from 0 to 100 (by 5).
SimpleThreadDemo is the same example as aSyncTaskDemo, but uses threads and handlers. Basically to see the difference in complexity between the two.
SimpleThreadDemo2 is the same example as aSyncTaskDemo and SimpleThreadDemo, but uses the runOnUiThread method.
TheadDemo is example using threads in a more complex where an AsyncTask may not work as well. It draws when the uses is touching the screen.