This extension will enable you to send push Notifications
    from your TYPO3 site straight to your visitors mobile devices. Create an API
    key in PushPro, paste it into your PushPro extension for TYPO3 and your website
    is ready to send push notifications! When your audience visits your website,
    they will now see an opt-in request for push notifications. If they accept,
    you are ready to engage with them. PushPro is a revolutionary way to engage
    with your mobile visitors. Interact directly by sending Push Notifications to
    your subscribers without a native mobile app, straight from your website