Just having a little tinker with xamarin and loving it. I was wondering, what is considered the best way to get a unique device ID which will be consistent across Android + iOS and which return same result even if device has it's firmware flashed etc. I was thinking the IMEI would do but that doesn't' seem possible for iOS anymore? I'd even need something that runs on iPod/iPad etc so guess IMEI not best option anwyay. A mix of MAC address perhaps? Is there a best-practice way of doing this which will be consistent?