Background

Smartphone video magnifier apps are being used by millions of people to assist their vision. To understand the behaviour of app users, an exploratory investigation was conducted based on ‘big data’ collected from their daily uses.

Method

A mobile magnification app was developed with embedded analytics data collection modules. Seven months after it was released to the public, 30 days of app use data were collected from 16,787 active users across 129 countries. App launches and function use were analysed.

Results

The app was most commonly used for one to three minutes a day, while a very small portion of users (0.5 per cent) used it over 100 times within the month and over 30 minutes each time. Some of the focused objects (13 per cent with Apple iPhone and 21 per cent with Apple iPad) were further than two metres away. Two functions that can be used to address the image shaking problem – live image stabilisation and snapshot – were compared, and it was found the former was used more often than the latter in terms of event/launch ratio and event duration. The flash light function (daily mean 209 seconds per device) was used more than focus locking (47 seconds) and inverted colour (28 seconds).

Conclusions

The mobile magnification app was mostly used for brief spot reading, while long reading occurred as well. As versatile devices, smartphones were used for near and sometimes far vision reading. This study presents a novel methodology helpful for understanding the behaviour of users and evaluating the utility of specific functions.