Table 3 Mobile phone categories according to the 36 studies

Mobile applications

Mobile applications, commonly referred to as mobile apps, are software programs designed to run on a mobile device, such as a smartphone or tablet. Many mobile apps have corresponding programs meant to run on desktop computers. This category comprises mobile apps, iPhone apps, smartphone apps, mobile software and m-learning platforms that were run on mobile phone or smartphone.

18

[53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70]

Short message service

Short message service (SMS) is a service for sending electronic message to and from a mobile phone. Messages are usually no longer than 160 alpha-numeric characters and contain no images or graphics. SMS is also known as text messaging.

7

[71,72,73,74,75,76,77]

Camera phone

A camera phone is a mobile phone that can take pictures and record video clips. Most new cellular phones are already equipped with cameras which include an image sensor, the lens and microelectronic mechanical system. Smartphone cameras are used for image processing and visual readout.

6

[78,79,80,81,82,83]

Mobile phone tracking data

Mobile phone tracking data are often call detail records (CDR) that log the location of mobile phone users when they make telecommunication transactions, such as a phone call or text message. This category comprises mobile phone signals.

4

[84,85,86,87]

Simple mobile communication

Simple mobile phone communication involves the use of mobile phone numbers to allow contact with others including voice communication (e.g. calls).

1

[88]