The Twitter for iPhone app is currently supporting the iPhone 6 Plus model only and is not functional on the iPhone 6 at the time of writing. First reported by 9to5Mac, the new landscape mode lets users to navigate the timeline, compose tweets, and even check direct messages in landscape mode. The landscape mode also allows users to view message threads while replying to a current thread.
Considering that the new landscape model is available to limited number of iPhone 6 Plus users, we can assume that Twitter may be still testing the feature on limited devices ahead of a broader rollout.
Recently Twitter was also reported to be testing a new feature that showed 'News' tab in its mobile app. Several reports on the Internet claimed that select Twitter users in the US were able to see the new section in their mobile apps dubbed 'News.'
The new Twitter feature included a list of trending news stories along with their headlines. On tapping the headline of the news story, a dedicated screen for the article opens up, showing the news story with an image, and also the top tweet section below the story. A Twitter spokesperson had confirmed the experiment and said, "We're experimenting with a news experience on iOS and Android as we continue to explore new ways to surface the best content to users."
We can expect that Twitter may introduce the new landscape mode and the 'News' tab feature under its anticipated Project Lightning. The details about the yet-to-be-announced Project Lightning were reported in June. Twitter is said to start curating tweets on live events in an attempt to make the platform more user friendly for real-time news feeds.