@treeplanter is a paid voting bot which uses part of each payment to plant trees. I like to use them to give extra upvotes to posts of new members as my voting power isn't large enough to have a big impact sometimes.
Think they require all votes be for someone else, that is you can't buy your own vote from them. Or at least that is how it was at one time, but I've not paid close enough attention to know if that is still true.
Basically I donated 0.10 SBD to get you a vote and help plant a tree. It's a Win-Win to me.