Clash of Town halls!

I was thinking of a good idea!!, if Supercell makes an clash of clans app where you can pick a town hall lvl that you are and have all the stuff available for that town hall. Walls, defense, resources, etc... In this app you could make and mess around with different types of ways you would like to build your town so you don't mess around with your actual town because you might not have enough time/shield. My CoC game name is cj111dbz and this is my idea or a new app that would be helpful for a lot of people!! Thanks!