Samsung Galaxy S4 Customer Consultant Manual page 68

Part 2 > Q110: Magnification gestures (1/2)
Q : When I touch the screen, it doesn't respond very well, especially when using the Dial Pad, Calculator, Keyboards.
What's the problem?
A : Sorry for your inconvenience.
First of all, check the Magnification gestures option in the Accessibility settings.
Magnification gesture option is a menu for the visually impaired, and when this feature is enabled you can zoom in and out
by triple tapping the screen. It's Google concept and embedded from Galaxy S4 Jelly Bean V4.2
If Magnification gestures option turned on, the whole touch response can be slower on your device
due to time margin required for the operation of triple touching .
Triple tap
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