Minecraft PE does not save information on servers, it saves it on the device's local storage. If he was playing on an Android with removable storage, the transfer is as simple as using the old card in the new device.

If the old broken device can still open Minecraft then you can transfer the world by hosting a LAN game from it, joining it with the new device and hitting Quit and Copy World in the Pause menu.

If not, you'll have to transfer the data across using a USB cable via a computer. If the old device is broken to the point where this won't work, there's not much you can do I'm afraid.

Unfortunately you cannot import a world that requires cross-platform, However, you can try to export a map of your world on your Android using a File Manager but it will require your iPhone to be jailbroken which isn't recommended and is very buggy, I suggest you put in a suggestion to the Minecraft Pocket Edition team suggesting for the availbitly of exporting maps button included in the next update,

Hope I helped.