Seconded! I use the paid version but the free version supports Facebook messenger just fine. I just got my brother on it yesterday and he already recommended it to everyone fed up with the new change.

I had an ancient account, over a decade I guess, back when I was on AIM, ICQ and MSN, I think? I recently signed back up for just this reason.

So far, so good! I InApp'd a month, but will likely get a year's worth at renewal.