How can I use a smartphone/tablet without being distracted by it in classrooms? I want to use an android phone without being distracted. I want to be able to block calling applications such as the calling feature in whatsapp, facebook messenger, viber calls, as well as google hangouts. There are some of my friends who directly call me when seeing my online.
Just simply remove the apps from your tablet or disable them if you cant delete them.

If you want them to stay on the tablet then go into the app settings and configure them respectively. 

Also Do Not Disturb is your friend, I'd put it on a schedule and set it.