It turns out that mobile phones have such functions! (Especially the third type)

In addition to making phone calls, you can do four things on your mobile phone. You may not know before.

We may be more or less aware of some emergency self-help methods, but you may not know that your mobile phone can save your life at a crucial moment. Let's take a look at the following content to understand what your mobile phone can do!
1. Emergencies
All mobile phones around the world can call a common emergency number of 112. When you join us and find that your region is not covered by a mobile phone signal, you are in an emergency, you can call 112 on your mobile phone, because your mobile phone will automatically search for all available networks and create an emergency call. Even if your phone is locked on the keyboard, you can call 112. Try it!
2. Left the vehicle remote control in the car?
Can the remote control be enabled for your vehicle? If you can, one day, you will find that you have a mobile phone that is very convenient, and you can use a mobile phone to dial the mobile phone of your family, take your phone 1 feet away from the door, and press the unlock key on the remote control next to your phone with the remote control. This method works no matter how far you drive away from home.
3. Invisible backup battery (tested by a user, only Nokia can currently be used)
Your cell phone is underpowered. to enable it to continue using it, press the * 3370 # key and the phone will restart. After it is started, you will find that the power usage has increased by 50%. When the hidden backup battery is used up, you have to charge it. When you recharge the battery, the invisible backup battery is also charged. You can use this method when the power usage is low next time. I know this is useful if the cell phone power is insufficient in an emergency.

4. Is the mobile phone stolen? There is a way to make thieves useless, hey!
To view the serial number of your mobile phone, type * #0 6 #
The 15-digit serial number will appear on the mobile phone screen. Every mobile phone in the world has a unique serial number, which is recorded and saved. One day, if your mobile phone is stolen, you can call your mobile phone provider and provide your mobile phone serial number. They will shield your mobile phone, even if the thief changes the SIM card, still unable to use, your mobile phone has become useless for thieves. If every mobile phone holder in the world does this, it makes no sense to steal a mobile phone.
In Australia, the police even set up a stolen mobile phone database. If your mobile phone is found, it can be returned to you.