rn-fade-edge.jsx

import { MaskedViewIOS, View } from "react-native";
import LinearGradient from "react-native-linear-gradient";

// ...

const MaskedView = Platform.OS == "ios" ? MaskedViewIOS : View;

render = () => {
        return (
            <MaskedView
                style={styles.outputView}
                maskElement={
                    <LinearGradient
                        locations={[0, 0.1, 0.9, 1]}
                        colors={[
                            "transparent",
                            "black",
                            "black",
                            "transparent"
                        ]}
                        style={styles.outputView}
                    />
                }
            >
                <ScrollView
                    style={styles.outputView}        
                />
            </MaskedView>
        );
};