When you reach level 24 and unlock the telephone you will have a choice of three helpers. You can only choose one of them. Note: The helpers do things automatically. They know what to do and when to do it.

Bartender: Gives drinks to people when they become impatient at their tables. Note: He is the most helpful helper.
Cleaner: Picks up the checks and cleans the tables.
Singers: This posse will play music to entertain people in line.