You can edit your posts. I edit all the time because of spelling errors and at times I think I might have been nasty. So I edit out the nastiness.

After you post, you just click on the arrow on the right side of the post and there is an edit option. The options are edit the answer or delete the answer. Not sure if this just pertains to answers that are made responding to other peoples posts.

It onlY shows unfollow or delete post on my phone. I will see if it works on my tablet. What about comments, can they be edited?