With some major design changes it feels like a whole new app. There's some hidden easter eggs as well that I’ve noticed people may have missed. If you go into setting, tap Support Tweetbot, and give them a tip you can unlock different themes. After that go into display and you can now change your themes. My personal favorite is Pumpkin.
This was something I hadn't noticed until Chris told me about it. I'm currently using the Manhattan theme.