I got this neat little trick from my colleague Petr. Dialing *3001#12345#* on your iPhone launches a hidden app called Field test. In it, you’ll find a lot of detailed information about your network. You can disable wifi to see even more data.

To be honest, I don’t even know what half of those values mean, but you can easily Google for them. The EF-ICCID value in SIM Info can be useful even for non-developers. It’s the ID of your SIM card, the one your operator often times asks for. This way, you don’t have to take out the card from the device.