Retina for all iOS devices

hello , is there a simple way to force all device to non retina? i believe by default the iOS build is set to retina, should i go through to each devices and specify their respective non native resolution? it s a bit cumbersome . knowing the amount of devices here
thanks

(In code) Set the resolution to the screens current resolution divided by 2.

Theoretically, it should do what you are asking on all iOS devices.