Apple iOS and Google Android devices already have the native screenshot feature. Now even on Windows Phone 8 devices you really don't have to install third party apps to take a screengrab of a coupon or flight ticket number.
Just follow this simple guide to take screenshots quickly and efficiently.
Locate the power button on the smartphone. It's the same one used for locking the screen or putting the display into sleep state.
Second most important is the capacitive Windows Phone logo key. It is not actually a button so users need to press it simultaneously with the power key.
Press the Power and Windows Key together till you hear the image capture sound. Next, you'll see the notification of 'Saving to Screenshots' in the notification bar.
Best part of Windows Phone 8 is that once enabled, all screenshots taken get backed up to the SkyDrive. That allows the user flexibility to access those screenshots from anywhere.