How often do you use your phone at work?

Several times a day! If you're into any tech job that is not very sensitive / deal with government secrets, I don't think using a phone would be a problem nowadays...

Every 30 or 45 minutes every after call meetings.

As a product designer, I pick up my phone almost every half hour. This is insane. My neck is already hurting unbearably.

Every two 2 hours, during my breaks.