TECHNOLOGY CITY

IMEI (International Mobile Equipment Identity) is 14 digit numbers on GSM phone that used by GSM operator to identify valid devices and therefore can be used for stopping a stolen phone from accessing that network.

When you bought a phone, you must surely IMEI is on the phone box. IMEI can be displayed on the screen of the phone by entering *#06# into the keypad on most phones.

As a smartphone, Android's phone is equipped by many different functional sensor. To know that all sensor is working well in a phone, you can install "Android Sensor Box" from Google Play. After installing, you can testing many sensor, such as :

Accelerometer sensor is applied to detect device directions (auto rotate screen when the device is rotated vertically). It is also widely used in game development.

Proximity sensor measures the distance between two objects, usally the device screen and our hands or face. Test the effect by moving your hand forward and backward in front of the device in Andorid Sensor Box.

Temperature sensor provides information about your device temperature, thus you can take action when temperature is too low or too high.

Gyroscope sensor can measure six directions at a time. You will be able to see the effects immediately by rotating your phone slightly. Now, gyroscope sensor is mostly used in 3D game development, and possibly indoor navigation in future. 

Sound sensor detects the sound intensity around you and provides you detailed information about the intensity changes.

Magnetic sensor is used in many areas like metal detection and compass, which bring us lot convenience in our life.

Pressure sensor is used to detect environmental pressure, thus to forecast weaher and temperature.
It was usually used with magentic sensor in navigation.