You can display notification when application is in background by using Rho.Notification Api.
Kindly go through docs @ http://docs.rhomobile.com/en/5.0.0/api/Notification#mshowPopupSTATIC
Rho.Notification.showPopup(The specified item was not found.
The above code will show a notification in notification bar when app is in background with customized icon.
indeed, when app is in background this makes a message appear in the notification/status section of the phone (haven't tested it on iOS though)
the only annoying thing is, that when tapping on the notification, I end up in the application and am presented with a dialog/popup window where I have to click a button ... If I leave out the button hash, the popup never leaves, and effectively blocks the UI. Obviously I don't want a popup in the UI if the notification is tapped
Have you tried types: [Rho.Notification.TYPE_NOTIFICATION]
On Iphone it will not work as this property applicable to only android.