Comment Just switch it to airplane mode. (Score 1) 87
There's also the "Detox" exercise of leaving your phone at home. and only taking it with you when it's absolutely necessary for example to work if you have to use a third factor authentication application to get into your computer)
Just switch on "airplane mode". No incoming calls, message notifications, or app push crud. (If you've got any apps, other than alarm/calendar notices for your schedule reminders which YOU set up, that poke brain-derailng messages at you, disable (or delete) them.)
Then get into the habit of not going to it for anything non-essential while in this mode.
Now you can use it for a key, or wallet, or whatever, if you must, without it constantly killing your attention span with interruptions. Yet you can always turn it back on to make a call, or in the timeslot you reserved for handling this trivia.
No incoming calls, though. (What a relief: No phone spammers!)