To name a few of those casino apps that pay real money with no deposit, there is:
1
PokerStars Casino -R$100 Bonus Play.
2
BetMGM Casino -R$25 No Deposit Bonus.
3
Borgata Casino -R$20 No Deposit Bonus.
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.