Tapbots said on Feb. 26, 2015:

Our goal is to finish major updates to all of our apps before WWDC. We never want to be in the middle of a huge update or new app through the summer because WWDC has a tendency to derail us with significant OS changes. We are going to do a better job keeping our current apps up to date with each new OS release.

We’ve been teasing about Tweetbot 2 for Yosemite on Twitter and we are working hard to get this into a solid beta state. This app has become a huge rewrite and has taken so much longer than we had hoped, but it is coming along very nicely. It will be a free update to show our appreciation for your support in the past few years.

We are also working on getting major updates to Tweetbot for iOS out. This will include landscape mode for iOS (finally), and the highly anticipated update to the iPad version. We plan on putting a lot of time and love into making Tweetbot a better product this year.

Tweetbot for iPad 自從 iOS 6 以後就沒有更新，Tweetbot for Mac 也是在 OSX 10.8 以後沒有更新。因此以上聲明根本就是自打嘴巴。