You are not happy that the mobile app can't do real mining? But if it was the case, you would receive maybe 1 ETN each 2-3 months and your phone would broke faster.
I think you should be happy that Electroneum is giving free ETN with the app without using any ressources on your phone. Except some disk space and the network to just verify the connection with the server.
You should look at it as a mini-game who reward people who use it. It is a "mining simulator".