But what I must tell you related to the effects is that it uses an active background (that blue characteristic clouds are moving), and it seems that this slows my phone down. Considering that this is a Nexus One and I feel that clouds moving, I don't know how this application works on slower devices. Even if the application has many options, the interface makes it seem...a bit too simple.
In my point of view, Seesmic is better than this Twitter app. You can get Twitter's own application via the Android Market by searching "Twitter" (first app).