Sign up for a player's card.\n\n As you gamble, you'll gain player's points that can go towards free benefits which can include a free or upgraded room. You can sign up for a player's card on the casino's website or you can go to the front desk and request one.
All in all, there are free slots that pay real money, but you will have to be playing at real money online casinos as opposed to social casinos on slot apps, or playing titles in demo mode.
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.