An early Australianism (circa early 20th century), said during moments of anxious expectation, generally after the commencement of moments of chance, for example awaiting imminent news; the results of a sports match, or an attempted task with an unknown, random result.
Historically the phrase entered the vernacular in the first half of the 20th century, coined during betting matches of 'two-up', but the etymology may stem from roulette.
During a dice roll, while still shaking the dice: "Come in, spinner!"
This is a phrase used in Australia when someone has been tricked or fooled. Usually when someone has been lured in and deceived in a cheeky way.
An example of when it is used might be if you were tricked or talked into placing a bet with someone when it was clear afterwards you couldn’t win. After you lost, the winner might say to you in a cheeky fashion ‘come in spinner’.