One of the most important addons we had in our previous VB forum was Tweetposter (link). What it does basically, It allows you to tweet threads, either automatically or manually, on a usergroup permission basis. In our previous forum, we had the automatic tweeting disabled, and allowed only our moderators to tweet any thread to our Twitter account, which was much better than sharing the Username/Password of our Twitter account with them. The current addon in vb.org is outdated and I had a vb developer update for us so we have a working mod for vb. If there is a developer who can port this to Xenforo, I would pay for it and release to RM for free under his/her name.