This chat is live IRC chat only, not the forum
threads.
You are able to post in almost any
thread now. Just browse on Tapatalk to any thread of interest in any of the sub-forums listed. I see you've posted in a couple now; notice that the thread name typically states the topic. For example, a thread name of Abbreviations wouldn't be the place to talk about buying a Provari.

Browse to the sub-forum New Members, and notice all the threads as you scroll, or start a new one introducing yourself.
So the link I posted is Live IRC chat, which does work on Android. I assume it works on iPhone as well, but I haven't personally tested it. There are IRC apps available to use for it as well.
I hope this helps!