Novel Star seems to be the most desperate. Honestly, my guess is a lot of the users are from that app and create accounts here to get you to join their shitty app. I got a post from one recently that shared a Facebook link for their writing competition or whatever, and the posts from that account have hundreds of positive comments. Yet they all have that robotic vibe to them.
Feel free to check it out if you'd like. Just search Novel Star on Facebook. Don't wanna share their links around. They'd probably love that.
I used to assume that all these are just mere bots who won't reply, but a while back on Wattpad, I played around and messaged one of them (from a different app) about how it goes against guidelines to spam. Turns out she was a very defenseless and manipulative person. Went on about how I ruined her night and she loved my story, which she couldn't even be bothered name or show she read it, and only wanted to help me make money. Anything that reaches out to people like this is highly unprofessional and only makes the app worse.