device any clever maneuver; "he would stoop to any device to win a point"; "it was a great sales gimmick"; "a cheap promotions gimmick for greedy businessmen"
prompter -
someone who assists a performer by providing the next words of a forgotten speech
assistant,
helper,
help,
supporter a person who contributes to the fulfillment of a need or furtherance of an effort or purpose; "my invaluable assistant"; "they hired additional help to finish the work"
