In plickers, you still get to see responses on the cards and since you know the students in most cases, you can identify and if you want to single out a student (which I'm sure most teachers don't do), you can do it. "piCards: Anonymous Polling App" is a truly anonymous feedback system where you cannot know the students' response unless you read their cards. This will also give more confidence to students to freely answer without worrying about getting it right.