Not sure with Tapatalk, but on a desktop you go to their name, click on it and it should open a little pop up, on that pop up is a list of items like: Profile page, Start a conversation, Follow, Ignore, Photo's, View trading profile.
I am guessing on Tapatalk this will open in a new page as opposed to a pop up, but not sure, hopefully someone else will chime in!
Luke.