Many Android developers ask how to start the default twitter client from their application. Which Intent should you use?
It is often advised to send an Intent with ACTION_SEND. However, many programs will fire up: Gmail, SMS send, dropbox, twitter clients, MMS Send, flickr send, etc. This is too broad.
On the other hand, some people advise to filter on the MIME type application/twitter. But this is too restrictive: very few clients will recognize this unofficial/non-standardized MIME type (twidroid is among them, but HTC default client is not).
Eventually, I came up with the following solution: list all applications that reply to ACTION_SEND and filter on known package names.
Hope this helps!