From what I've been reading so far, the growing consensus is Steemit and Busy. However, since the challenge is originating on Steemit, and isn't a vlog, image or meme, there's bound to be more people using the long form versions of the STEEM apps. I thought, though, there would be more people experimenting with the others at least. I haven't read that many, though, so maybe just the first few of us are the blogging types.