Some posts shared through Buffer Publish will display a source stamp that mentions that you used Buffer to share the post. This source stamp is something that is added by the social network and some customers have asked if it's possible to remove the mention of Buffer. Sadly, this is not possible as it's something that these social networks require of all third party apps. This article outlines where you will see these stamps.
Posts published to Facebook Pages will display a "Published by Buffer" link, but this is only visible to Page Admins. Your followers will not see this link.
Posts published to Facebook Groups will display a "Buffer" link, which is visible to everyone.
Please note, posts published to a Facebook Group will appear as being posted by the Facebook member who connected the Group to Publish. Learn more about this here.
All posts on Twitter will show a "Tweet Source Label", which shows if the tweet was posted via Twitter itself or through a third party source like Buffer. You can learn more about these labels here. It's worth noting that this source label may not be visible in all versions of Twitter.
Posts published to LinkedIn Pages will display a "Posted by *name*" link, where *name* would be the person who authorized the connection with Buffer. So, if Angela Smith connected the LinkedIn Page to the Publish account, all posts would display "Posted by Angela Smith". However, this is only visible to Page Admins. Your followers will not see this link.