This app does not save your data what so ever. The app generates links for publishing messages to a specific channel using the public API. These links are immediatly shared with (YOU) the user and not saved in any larger extent than what slack saves.
We do not take responsibility for what you do with this app. It is up to you to evaluate the security implications from using it, while we just promise not to use any data to deliberately cause any harm or annoyance.