I have been struggling to send text from my app to Twitter.
The code below works to bring up a list of apps such as Bluetooth, Gmail, Facebook and Twitter, but when
you can simply open the URL with the text and Twitter App will do it. ;)
String url = "http://www.twitter.com/intent/tweet?url=YOURURL&text=YOURTEXT";
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
and it will also open the browser to login at the tweet if twitter app is not found.