show 2 items per row[react native]

You can try the flat list from react native. where in you can specific the number of columns and also can mention the vertical direction or horizontal direction. Sample code:

<FlatList
data={this.props.data}
keyExtractor={this._keyExtractor}     //has to be unique   
renderItem={this._renderItem} //method to render the data in the way you want using styling u need
horizontal={false}
numColumns={2}
          />

Refer https://facebook.github.io/react-native/docs/flatlist.html for more.

The correct way to do it would be with flexBasis, with a value set to (1/n)% where n is the desired # of rows > 0. For two rows:

.parent {
    flex: 1;
    flexWrap: 'wrap';
    flexDirecton: 'row';
}
.child {
    flexBasis: '50%';
}

To make a 2 row grid using ListView you could use this code as an example:

renderGridItem( item ){
    return (<TouchableOpacity style={styles.gridItem}>
        <View style={[styles.gridItemImage, justifyContent:'center', alignItems:'center'}]}>
            <Text style={{fontSize:25, color:'white'}}>
                {item.fields.name.charAt(0).toUpperCase()}
            </Text>
        </View>
        <Text style={styles.gridItemText}>{item.fields.name}</Text> 
    </TouchableOpacity>
    );
}

renderCategories(){

    var listItems = this.dsinit.cloneWithRows(this.state.dataSource);

    return (
        <ScrollView style={{backgroundColor: '#E8E8E8', flex: 1}} >
            <ListView 
                contentContainerStyle={styles.grid}
                dataSource={listItems}
                renderRow={(item) => this.renderGridItem(item)}
            />
        </ScrollView>
    );
}

const styles = StyleSheet.create({
    grid: {
        justifyContent: 'center',
        flexDirection: 'row',
        flexWrap: 'wrap',
        flex: 1,
    },
    gridItem: {
        margin:5,
        width: 150,
        height: 150,
        justifyContent: 'center',
        alignItems: 'center',
    },
    gridItemImage: {
        width: 100,
        height: 100,
        borderWidth: 1.5, 
        borderColor: 'white',
        borderRadius: 50,
    },
    gridItemText: {
        marginTop: 5,
        textAlign:'center',
    },
});

Change styles to choose how many rows you want to see on screen. This code is responsive.