I think @steem-bounty. Though i don't have exclusive knowledge of many bots, but I've read about the principles of steem-bounty and i think they are the best that i know of.
Not only do their feature draw more readers to the content it's attached, rewarding the user, it also rewards the readers and commenters through the 80/20 stuff. Honestly they are the best.
Well thank you. We are happy you like it!
You are welcome
Just been reading up on this tool, I think it's going to be a winner and will likely publicise it and use it later today 👍🏾