Click on the Microblog button within the mobile navigation.

Then, click on the plus button  in the bottom left corner of the app.

Enter the content of your post.

In the Choose topic section, click on the arrow button to the very right of the app. Select the topic of your post.

Finally, click on the Create button in the top right corner.

Replies work in the same way as new comments.

To reply to a microblog post or a comment, click on the Reply button in the bottom right corner of a post or comment.

Type in your reply and click on the Send button.