Free play refers to a specific type of promotion that is offered by some casinos, in which players are given a certain amount of money to use on certain games, usually slot machines. This money is not real money, but rather a form of "play money" that can be used to play the games but cannot be cashed out or withdrawn.

Yes, some free slot machine apps offer the chance to win real money. These apps often have in-app purchases or advertisements that generate revenue for the developers, and they might also have a system where you can earn virtual currency or tokens by playing the free slot games.