You will find some social casinos on the App Store or Google Play Store that won't pay real money, but you can win real money on slot apps that we have recommended.
You first need to create an account at a licensed online casino. Then, deposit funds to your account through an accepted payment method. Choose the slots game you want to play, start it up, and set the size of the bet. Now, you just have to press the spin button to play one round.