It's been a while since I played on the bustabit and I forgot if they do have shower, do they have?
I am unfortunately too seldom on Bustabit, so I can only answer this question for Bustadice. There is a "Tipping" system where you can donate coins to certain users (= username): 
I would not have seen chatrain functionalities yet, but to be honest I don't have the chats open when I play.
Quoting an old post of mines to make a quick summary of who came first and when. Good old times
Very nice, thanks! Afaik FortuneJack would also have to exist for a similar length of time, right? I remember that they started around 2014 with signature campaigns here in the forum.