Creating Native AdView

1. open xcode with your current Flutter Ios project.

2. Add Empty .xib file to Runner.

3. Name it NativeAdView

4. Open that file as source code.

5. Add Below code into it.

NativeAdView.xib

<?xml version="1.0" encoding="UTF-8"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="21507" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" colorMatched="YES">
    <device id="retina4_7" orientation="portrait" appearance="light"/>
    <dependencies>
        <deployment version="2048" identifier="iOS"/>
        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="21505"/>
        <capability name="System colors in document resources" minToolsVersion="11.0"/>
        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
    </dependencies>
    <objects>
        <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner"/>
        <placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
        <view contentMode="scaleToFill" id="iN0-l3-epB" customClass="GADNativeAdView">
            <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
            <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
            <subviews>
                <imageView userInteractionEnabled="NO" contentMode="scaleAspectFit" horizontalHuggingPriority="251" verticalHuggingPriority="251" translatesAutoresizingMaskIntoConstraints="NO" id="iNa-bH-h1m">
                    <rect key="frame" x="15" y="15.5" width="40" height="40"/>
                    <constraints>
                        <constraint firstAttribute="height" constant="40" id="ICz-3W-FQf"/>
                        <constraint firstAttribute="width" constant="40" id="vY6-8D-xIn"/>
                    </constraints>
                </imageView>
                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Advertiser" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="GTT-Yh-eSq">
                    <rect key="frame" x="63" y="38.5" width="66.5" height="17"/>
                    <fontDescription key="fontDescription" type="system" pointSize="14"/>
                    <color key="textColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                    <nil key="highlightedColor"/>
                </label>
                <imageView userInteractionEnabled="NO" contentMode="scaleToFill" horizontalHuggingPriority="251" verticalHuggingPriority="251" placeholderIntrinsicWidth="100" placeholderIntrinsicHeight="17" translatesAutoresizingMaskIntoConstraints="NO" id="2Of-AP-0h9">
                    <rect key="frame" x="129.5" y="38.5" width="100" height="17"/>
                    <constraints>
                        <constraint firstAttribute="height" constant="17" id="jBW-Cz-Kyc"/>
                        <constraint firstAttribute="width" constant="100" id="sXk-zk-NI0"/>
                    </constraints>
                </imageView>
                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" verticalCompressionResistancePriority="751" text="Body that is really really long and can take up to two lines or sometimes even more." textAlignment="justified" lineBreakMode="tailTruncation" numberOfLines="0" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="PEQ-D9-2Vv">
                    <rect key="frame" x="15" y="63.5" width="536" height="33.5"/>
                    <fontDescription key="fontDescription" type="system" pointSize="14"/>
                    <color key="textColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                    <color key="highlightedColor" systemColor="labelColor"/>
                </label>
                <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="E5w-YA-UY8">
                    <rect key="frame" x="504" y="259.5" width="47" height="34"/>
                    <fontDescription key="fontDescription" type="system" pointSize="18"/>
                    <state key="normal" title="Install">
                        <color key="titleColor" systemColor="systemYellowColor"/>
                        <color key="titleShadowColor" red="0.5" green="0.5" blue="0.5" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                    </state>
                </button>
                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Price" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="Ysb-of-cat">
                    <rect key="frame" x="416" y="268" width="33" height="17"/>
                    <fontDescription key="fontDescription" type="system" pointSize="14"/>
                    <color key="textColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                    <nil key="highlightedColor"/>
                </label>
                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Store" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="hwF-UL-Q8H">
                    <rect key="frame" x="459" y="268" width="35" height="17"/>
                    <fontDescription key="fontDescription" type="system" pointSize="14"/>
                    <color key="textColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                    <nil key="highlightedColor"/>
                </label>
                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" verticalHuggingPriority="251" horizontalCompressionResistancePriority="751" text="Headline" textAlignment="justified" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="beR-eV-DX1">
                    <rect key="frame" x="63" y="10" width="483" height="20.5"/>
                    <constraints>
                        <constraint firstAttribute="height" constant="20.5" id="6r8-Hu-d0y"/>
                    </constraints>
                    <fontDescription key="fontDescription" type="system" pointSize="17"/>
                    <color key="textColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                    <nil key="highlightedColor"/>
                </label>
                <view contentMode="scaleToFill" id="fNp-yu-K4i" customClass="GADMediaView">
                    <rect key="frame" x="37" y="102" width="300" height="150"/>
                    <autoresizingMask key="autoresizingMask"/>
                    <constraints>
                        <constraint firstAttribute="height" priority="750" constant="150" id="71m-kn-7Ug"/>
                        <constraint firstAttribute="width" constant="250" id="e3T-fD-di4"/>
                    </constraints>
                </view>
                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Ad" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="lp1-oz-XOs">
                    <rect key="frame" x="0.0" y="0.0" width="15" height="15"/>
                    <color key="backgroundColor" red="1" green="0.80000001190000003" blue="0.40000000600000002" alpha="1" colorSpace="calibratedRGB"/>
                    <constraints>
                        <constraint firstAttribute="width" relation="greaterThanOrEqual" constant="15" id="Twa-Vk-uWQ"/>
                        <constraint firstAttribute="height" constant="15" id="k8m-kJ-CF5"/>
                    </constraints>
                    <fontDescription key="fontDescription" type="system" weight="semibold" pointSize="11"/>
                    <color key="textColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                    <nil key="highlightedColor"/>
                </label>
            </subviews>
            <color key="backgroundColor" white="0.15291942848640233" alpha="1" colorSpace="calibratedWhite"/>
            <constraints>
                <constraint firstItem="GTT-Yh-eSq" firstAttribute="leading" secondItem="beR-eV-DX1" secondAttribute="leading" id="0sB-Mk-EU6"/>
                <constraint firstItem="lp1-oz-XOs" firstAttribute="top" secondItem="iN0-l3-epB" secondAttribute="top" id="3lA-qv-Nkc"/>
                <constraint firstItem="Ysb-of-cat" firstAttribute="leading" relation="greaterThanOrEqual" secondItem="iN0-l3-epB" secondAttribute="leading" constant="20" symbolic="YES" id="3pc-w6-uy1"/>
                <constraint firstItem="PEQ-D9-2Vv" firstAttribute="top" relation="greaterThanOrEqual" secondItem="iNa-bH-h1m" secondAttribute="bottom" id="4S3-p0-z6A"/>
                <constraint firstAttribute="trailing" secondItem="PEQ-D9-2Vv" secondAttribute="trailing" constant="10" id="8U0-Fb-3R7"/>
                <constraint firstItem="iNa-bH-h1m" firstAttribute="leading" secondItem="iN0-l3-epB" secondAttribute="leading" constant="15" id="9WK-zC-xET"/>
                <constraint firstAttribute="trailing" secondItem="beR-eV-DX1" secondAttribute="trailing" constant="15" id="BcE-do-dNl"/>
                <constraint firstItem="lp1-oz-XOs" firstAttribute="left" secondItem="iN0-l3-epB" secondAttribute="left" id="BpX-yC-PZG"/>
                <constraint firstItem="PEQ-D9-2Vv" firstAttribute="top" secondItem="2Of-AP-0h9" secondAttribute="bottom" constant="8" symbolic="YES" id="CCg-xe-cKg"/>
                <constraint firstItem="2Of-AP-0h9" firstAttribute="top" secondItem="beR-eV-DX1" secondAttribute="bottom" constant="8" symbolic="YES" id="ESC-Pe-TXR"/>
                <constraint firstItem="iNa-bH-h1m" firstAttribute="bottom" secondItem="2Of-AP-0h9" secondAttribute="bottom" id="GwM-y0-1du"/>
                <constraint firstItem="beR-eV-DX1" firstAttribute="leading" secondItem="iNa-bH-h1m" secondAttribute="trailing" constant="8" symbolic="YES" id="MRN-dd-Oip"/>
                <constraint firstItem="2Of-AP-0h9" firstAttribute="leading" secondItem="GTT-Yh-eSq" secondAttribute="trailing" id="Med-Nd-wEo"/>
                <constraint firstItem="beR-eV-DX1" firstAttribute="top" secondItem="iN0-l3-epB" secondAttribute="top" constant="10" id="Mvs-eV-Wzb"/>
                <constraint firstItem="Ysb-of-cat" firstAttribute="centerY" secondItem="hwF-UL-Q8H" secondAttribute="centerY" id="Rud-i8-Myz"/>
                <constraint firstItem="fNp-yu-K4i" firstAttribute="centerX" secondItem="iN0-l3-epB" secondAttribute="centerX" id="TYN-lq-3DK"/>
                <constraint firstItem="fNp-yu-K4i" firstAttribute="top" secondItem="PEQ-D9-2Vv" secondAttribute="bottom" constant="5" id="V0m-hf-6NS"/>
                <constraint firstItem="GTT-Yh-eSq" firstAttribute="centerY" secondItem="2Of-AP-0h9" secondAttribute="centerY" id="YgR-kp-age"/>
                <constraint firstItem="hwF-UL-Q8H" firstAttribute="leading" secondItem="Ysb-of-cat" secondAttribute="trailing" constant="10" id="aLb-sm-wAb"/>
                <constraint firstAttribute="right" relation="greaterThanOrEqual" secondItem="lp1-oz-XOs" secondAttribute="right" constant="20" symbolic="YES" id="czi-qD-IaJ"/>
                <constraint firstAttribute="trailing" secondItem="E5w-YA-UY8" secondAttribute="trailing" constant="10" id="eNM-dN-tvx"/>
                <constraint firstItem="E5w-YA-UY8" firstAttribute="leading" secondItem="hwF-UL-Q8H" secondAttribute="trailing" constant="10" id="f39-vH-KWq"/>
                <constraint firstItem="iNa-bH-h1m" firstAttribute="leading" secondItem="PEQ-D9-2Vv" secondAttribute="leading" id="mof-5F-8vM"/>
                <constraint firstItem="E5w-YA-UY8" firstAttribute="centerY" secondItem="hwF-UL-Q8H" secondAttribute="centerY" id="rNj-VY-YrO"/>
                <constraint firstItem="E5w-YA-UY8" firstAttribute="top" secondItem="fNp-yu-K4i" secondAttribute="bottom" constant="7.5" id="rup-e7-1CR"/>
                <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="E5w-YA-UY8" secondAttribute="bottom" constant="20" symbolic="YES" id="uEI-XT-igi"/>
            </constraints>
            <connections>
                <outlet property="advertiserView" destination="GTT-Yh-eSq" id="bY8-5O-6fF"/>
                <outlet property="bodyView" destination="PEQ-D9-2Vv" id="Gpd-Q6-Byv"/>
                <outlet property="callToActionView" destination="E5w-YA-UY8" id="RCf-yK-s1x"/>
                <outlet property="headlineView" destination="beR-eV-DX1" id="d1E-ed-yel"/>
                <outlet property="iconView" destination="iNa-bH-h1m" id="gIe-xy-iwm"/>
                <outlet property="mediaView" destination="fNp-yu-K4i" id="624-ZP-L04"/>
                <outlet property="priceView" destination="Ysb-of-cat" id="L6Q-hd-uaJ"/>
                <outlet property="starRatingView" destination="2Of-AP-0h9" id="zCO-9D-S0V"/>
                <outlet property="storeView" destination="hwF-UL-Q8H" id="hRl-23-ce1"/>
            </connections>
            <point key="canvasLocation" x="13.768115942028986" y="-5.6919642857142856"/>
        </view>
    </objects>
    <resources>
        <systemColor name="labelColor">
            <color red="0.0" green="0.0" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
        </systemColor>
        <systemColor name="systemYellowColor">
            <color red="1" green="0.80000000000000004" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
        </systemColor>
    </resources>
</document>