If you’re a real perfectionist and what to know exactly how strong your iPhone signal is you’ll love this trick. By using this trick you’ll replace the five signal dots located at the upper-left corner which show how strong your signal is with a numerical value.

Here’s how:

If you press the Home Button you will exit Field Test mode and the negative numerical value will be replaced with the five signal dots once again. If you would like to make the change stick:

  • Hold down the Power button on the right hand side of your iPhone until the Slide Power Off appears;
  • Then release the Power button and hold down the Home button until you exit Field Test mode;
  • You will now be able to toggle between the negative numbers and the five dots if you tap on it.

To go back to the dots once again:

  • Go back to Field Test mode by dialling *3001#12345#* on your iPhone;
  • Then simply exit Field Test mode by pressing only the Home button and not holding down on the Power button as well.