When it comes to iPhones, there are numerous tips and tricks to make the battery last longer and the speed to run faster. However, there's also a code which can give you access to settings that you may not be aware of. According to the The Independent UK, accessing your iPhone's Field Mode will let you see information about your phone that's usually hidden. To see data on your iPhone's signal and internet connectivity, simply dial *3001#12345#*. This is the screen that should appear You'll then see a grey screen which will display all the information above. You can have a look around the different setting but to access the signal strength, follow these steps. First, hold down the Power button until “Slide to Power Off” appears. release the Power button and hold the Home button until Field Test quits Next, you should release the Power button and hold the Home button until Field Test quits. The signal strength indicator should appear in a little number icon in the top left-hand corner of your screen. You're looking for a signal of above -80 to have good coverage and if it's below -110, your phone is experiencing bad coverage. To alternate between the numbers and the standard dots that usually display, simply tap the icon in the top left corner.