what you mean by
it s an app so u need to install it and then install a theme from its store and DONE...!
there is nothing more than this
what is your problem?
have u got any error or something?
its not that simple, it says something about unsupported screen, i had this problem also with my lg g2 and the way i fixt that was to hide the navigation bar for this specific app (themer launcher) and it worked. but for the xperia z2 there is no option in the xperia setting screen to hide the navigation bar for certain apps in this case for the themer launcher.
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