Qt Quick QML AdMob Android iOS Realisation: http://forsk.ru (based on https://github.com/yevgeniy-logachev/QtAdMob)

admobctl.cpp

#include "admobctl.h"
#include "QtAdMob/QtAdMobBanner.h"
#include "QtAdMob/QtAdMobInterstitial.h"
#include <QtQml>
#include <QDebug>
#include <QTimer>

AdMobCtl::AdMobCtl(QObject *parent) : QObject(parent)
{
    m_Banner = CreateQtAdMobBanner();
    m_Banner->Initialize();
    m_Banner->SetSize(IQtAdMobBanner::Banner);

    m_Interstitial = CreateQtAdMobInterstitial();

    showedTimer = new QTimer(this);
    connect(showedTimer, SIGNAL(timeout()), this, SLOT(showedTimerSlot()));
    showedTimer->start(500);
}

AdMobCtl::~AdMobCtl()
{
    delete m_Banner;
    delete m_Interstitial;
}

void AdMobCtl::showedTimerSlot()
{
    //qDebug() << "showedTimerSlot" << m_Banner->IsShow();

    if (cachedBannerHeight != bannerHeight()) {
        cachedBannerHeight = bannerHeight();
        emit bannerHeightChanged(bannerHeight());
    }
    if (cachedBannerWidth != bannerWidth()) {
        cachedBannerWidth = bannerWidth();
        emit bannerWidthChanged(bannerWidth());
    }

    if (m_Banner->IsShow() && (showedTimer->interval() == 500)) {
        emit showed();
        showedTimer->stop();
        showedTimer->start(2000);
    }
}

void AdMobCtl::setBannerVisible(const bool visible)
{
    //qDebug() << "setBannerVisible" << visible;
    m_bannerVisible = visible;
    if (m_bannerVisible) {
        m_Banner->Show();
    } else {
        m_Banner->Hide();
    }
}

bool AdMobCtl::bannerVisible() const
{
    return m_bannerVisible;
}

void AdMobCtl::setBannerPosition(const QPoint position)
{
    //qDebug() << "new position" << position;
    m_position = position;
    //for example: QPoint position((width() - m_Banner->GetSizeInPixels().width()) * 0.5f, 0.0f);
    m_Banner->SetPosition(m_position);
}

QPoint AdMobCtl::bannerPosition() const
{
    return m_position;
}

int AdMobCtl::bannerWidth() const
{
    return m_Banner->GetSizeInPixels().width();
}

int AdMobCtl::bannerHeight() const
{
    return m_Banner->GetSizeInPixels().height();
}

void AdMobCtl::setUnitId(const QString &unitId)
{
    //qDebug() << "set unitId" << unitId << m_bannerVisible << m_interstitialEnabled;
    if (!m_initialized) {
        m_unitId = unitId;

        m_Banner->SetUnitId(m_unitId);
        m_Banner->SetPosition(m_position);
        //m_Banner->AddTestDevice("514ED2E95AD8EECE454CC5565326160A");
        //if (m_bannerVisible) {
        m_Banner->Show();
        //}

        m_Interstitial->LoadWithUnitId(m_unitId);

        if (m_interstitialEnabled)  {
            //m_Interstitial->AddTestDevice("514ED2E95AD8EECE454CC5565326160A");
            m_Interstitial->Show();
        }
        m_initialized = true;
    } else {
        qDebug() << "AdMob alredy initialized!";
    }
}

bool AdMobCtl::interstitialEnabled() const
{
    return m_interstitialEnabled;
}

void AdMobCtl::setInterstitialEnabled(bool interstitialEnabled)
{
    //qDebug() << "set m_interstitialEnabled" << interstitialEnabled;
    m_interstitialEnabled = interstitialEnabled;
    if (m_interstitialEnabled) {
        m_Interstitial->Show();
    }
}

admobctl.h

#ifndef ADMOBBANNERCTL_H
#define ADMOBBANNERCTL_H

#include <QObject>
#include <QPoint>

class IQtAdMobBanner;
class IQtAdMobInterstitial;
class QTimer;

class AdMobCtl : public QObject
{
    Q_OBJECT
    Q_PROPERTY(bool bannerVisible READ bannerVisible WRITE setBannerVisible)
    Q_PROPERTY(bool interstitialEnabled READ interstitialEnabled WRITE setInterstitialEnabled)

    Q_PROPERTY(QPoint bannerPosition READ bannerPosition WRITE setBannerPosition)
    Q_PROPERTY(int bannerHeight READ bannerHeight NOTIFY bannerHeightChanged)
    Q_PROPERTY(int bannerWidth READ bannerWidth NOTIFY bannerHeightChanged)
    Q_PROPERTY(QString unitId WRITE setUnitId)
public:
    explicit AdMobCtl(QObject *parent = 0);
    ~AdMobCtl();

signals:
    void showed();
    void  bannerHeightChanged(int height);
    void  bannerWidthChanged(int width);

public slots:
    void showedTimerSlot();

    void setBannerVisible(const bool bannerVisible);
    bool bannerVisible() const;

    bool interstitialEnabled() const;
    void setInterstitialEnabled(bool interstitialEnabled);

    void setBannerPosition(const QPoint bannerPosition);
    QPoint bannerPosition() const;

    int bannerHeight() const;

    int bannerWidth() const;

    void setUnitId(const QString &unitId);

private:
    IQtAdMobBanner *m_Banner;
    IQtAdMobInterstitial *m_Interstitial;
    bool m_bannerVisible, m_interstitialEnabled;
    QPoint m_position;
    QString m_unitId;
    bool m_initialized = false;
    QTimer *showedTimer;
    int cachedBannerHeight, cachedBannerWidth;
};

#endif // ADMOBBANNERCTL_H

main.cpp

#include <QApplication>
#include <QQmlApplicationEngine>
#include <admobctl.h>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    //AdMob http://forsk.ru
    qmlRegisterType<AdMobCtl>("ru.forsk.admobctl", 1, 0, "AdMobCtl");

    QQmlApplicationEngine engine;
    QString productType = QSysInfo::productType();
    if (productType == "windows") {
        engine.load(QUrl(QStringLiteral("../darkstories/qml/main.qml")));
    } else {
        engine.load(QUrl(QStringLiteral("qrc:/qml/main.qml")));
    }

    return app.exec();
}

main.qml

import QtQuick 2.4
import QtQuick.Window 2.2
import ru.forsk.admobctl 1.0

ApplicationWindow  {
    id: appWindow
    width: 480
    height: 800
    visible: true
    visibility: (Qt.platform.os == "android" || Qt.platform.os == "ios") ? Window.FullScreen : Window.Windowed

    AdMobCtl {
        id: adMobCtl
        interstitialEnabled: true
        bannerVisible: true
        unitId: "ca-app-pub-7212327600726803/6079324485"
        bannerPosition: Qt.point((appWindow.width - adMobCtl.bannerWidth) * 0.5, 0)
        onShowed: {
            console.log("change banner position!");
            bannerPosition = Qt.point((appWindow.width - adMobCtl.bannerWidth) * 0.5,
                                     (appWindow.height - adMobCtl.bannerHeight * 1.5))
        }
    }

    Rectangle {
        id: root
        anchors.fill: parent
        anchors.bottomMargin: adMobCtl.bannerHeight
        color: "white"
    }
}