Reading the list of Build Challenge ideas posted here:
https://www.stellar.org/developers/guides/things-to-build.html
I saw the suggestion for a slack bot and haven't seen any listed in slack's app directory, so I thought I'd build my own take on it.
My Initial plan is to build a bot that will let you get the balance of a wallet using a command. It will also let you store your own wallet addresses so you can issue a command such as, "get my balances" to see a list of your own slack balances. This should be going up on Slack in the next couple days.
From that point, I intend to add further horizon functionality such as searching by transaction id and listing transactions for a given wallet. This should also be going up soon.
Assuming there is some interest in this, I also have some further ideas for implementing a tip bot of sorts within slack teams, but I don't think that will be done by the submission date of the build challenge. Also, I don't want to dump too much time into this slack bot if others already have more fully featured slack bots built.