Earlier this year Twitter launched a new app, Twttr, intended as a place where it could test possible new features for the main app without exposing them to its many users too early. 

Since then it's largely appeared to be looking into the question of conversation threading - making it easier to follow a set of replies under a Tweet, and retain a clear sense for where you are in relation to the original Tweeter. 

Now, eagle-eyed users including Jan Manchun Wong, below, have spotted that the main Twitter.com web service is starting to use the threads as they were tested on Twttr, confirming that Twitter is in favour of rolling out the change more widely. 

The change adds grey lines and indents to conversations on the network, delineating how threads have progressed and showing digressions and off-shoots. Further Tweets by the author who started the conversation in the first place are marked with a microphone icon for the sake of clarity and authority. 

The feature may also let users focus on a new Tweet by tapping on it, showing that Tweet in relation to its replies, and indeed whatever it might have been replying to. 

Twitter has confirmed that the rollout of this feature will happen in 2020, without setting an exact timeline, but also said that the version people have found so far does not necessarily reflect the final set of features that it will go with. 

Other features being tested on Twttr may find their way onto the main social media network too, according to that spokesperson, but again without confirmation over exactly which.