In android, we can able to post a status to twitter by using jtwitter. Its very simple to post a status in twitter. For that we need jtwitter.jar. you can download the jwitter.jar from here
Post Status in Twitter Example :-
Create a new android project,
Add the below code in your AndroidManifest.xml for internet permission
[sourcecode language="xml"]
<uses-permission android:name="android.permission.INTERNET"/>
[/sourcecode]