I am using Echofon, Twitter client, for a long time, mainly because of its ability to synchronize timeline between several devices. I am using it on laptop and desktop as a Firefox plugin and on iPad as app.
I have tried several different clients, but realized that this synchronization is a killer feature for me.
But now it seems to be a history as Naan Studios announced that they are going to abandon all version except of mobile one.
So from unique multiplatform Twitter client with synchronization between several devices we have here a client like hundreds of other.