These cards are great to use with your attention-needy students!
In my classroom, I use them when a student is needing my attention/wants to talk to me when I am not available. I tell the student to leave it on their desk as a visual to me to make time to come to them as well as a visual to them that I know they want to talk to me. After a student receives a card they may not ask to speak to me again (I use the "asked and answered" strategy for this) and I have to get to them as soon as possible.
I hope this helps you!