I have found this on FlightRadar forum so have contacted manufacturer again
Why is the Flightradar24 not working on my tablet?
Flightradar24 is built based on Google Maps API. Google apps for Android, such as YouTube, Google Maps and Navigation, Gmail, and so on are Google properties that are not part of Android, and are licensed separately. That means that a tablet that is not Google certified, will not have all necessary files that are needed by Flightradar24 to work (Google Maps API). Even if you hack the tablet and install Google Play and Google Maps, there are still files missing in the system and Flightradar24 will not work. If you want to be sure that you can run Flightradar24 on your tablet, make sure to buy a Google certified unit from one of the major brands on the market.