Simple Push Notification app

Hello, I am looking for a developer to develop a very simple push notification app, cross platform, could be a web app (e.g. Ionic...) in order to send notification to all users who have downloaded the application, of course we also need a basic platform where the admin can send these notifications. The app is very simple, when you open it you can see that latest notifications from the last 24 hrs. of course a notification could come with an image attached to it.