Yes there are many that do. I have not found one Resteem Service That Was Worth Sending Even 0.001 SBD. Don't get ripped off here. If A Real Person's Account With 10,000 Plus Real Followers were to offer this it would not be broadcast and would cost a lot more than 1 or even 10 SBD. With that said let me point you in a great direction and also answer your questions in better detail.

One of the best support groups that is virtually free is @minnowsupport. It is a wonderful community of people trying to spread peace, love and abundance. This community has several free support bots that one can use on a post per day. Additionally they have workshops for writing and is a great place to network and meet people. It is kinda of difficult to figure out how to join and what to do. If you have the time it is worth reading about and trying to navigate all of the hurdles you must jump through to get it set-up. Here is there link... https://steemit.com/@minnowsupport

https://SteemThat.com is a great little small community that is growing daily. It is super easy to sign up and create your profile just like any social media website. We are building a website where it is easy to find all of the tools and docs you would need to be an excellent steemian. We also provide several tools that we built or others have let us use to help new members on steemit.com.

Our growing community chat is becoming more active as we launch more features and tools. We have AutoShare which as a member would help you out for free. It is not a lot right now as far as upvotes but it does help. I built https://steemthat.com after seeing several high quality posts only get 0.250 SBD while a picture taken from pixabay was getting 20.00 or 30.00 SBD. I knew honest high quality people needed a place to chat, message, form groups and share ideas and promote their posts and find real people to follow and make friends. It needed to be easy to join, benefit members and overtime grow with the community.

With that said let's answer a few more questions within your question. Yes. There are some bots on steemit that upvote posts because of things that you do. Steemish and SteemThatYes are very small but upvote when you use a special hashtag and are members of SteemThat.com. @gentlebot give large upvotes on comments that only he knows why but they are usually helpful comments. Thing1 and Thing2 also do these types of curations to help members. There are numerous #introduceyourself bots that auto upvote and often give tips to new comers. I have often said I will build a list and pat these folks on the back. Much of the info just isn't there to compile all of these and the hows and whys of what they do.

There are several cool mention bots.... @originalworks will show up when you mention it.
Another one is @steemprice which will show up and tell us the price of steem! Yes...
You Can Call My Cat If You Need A Smile. Catfacts are a plenty when you say @steemthatyes
@inertia built this I think and actually uses @catfacts for the original version. My cat dances and makes my boy smile and dance. Sometimes it makes me smile and dance...hehehe

Are there others? I am 100% sure there are others just not sure of all of them. I would love for all of the owners to join steemthat.com and help me update facts about their upvote bots. Their history and why they built them etc would be nice for users. Hope this reply helps you out. If you need anything just ask.