The participants who took phone breaks experienced the highest levels of mental depletion and were among the least capable of solving the puzzles afterwards. Their post-break efficiency and quickness was comparable to those with no break. Their number of word problems solved after the break was slightly better than those who took no break, but worse than all other participants.
Maybe one of the best productivity gifts I've ever received was the Rubik's cube I got this year for Christmas. It now sits on my desk and in an idle moment I pick it up and mix it up, maybe solve a step only to mix it up again. Yes I have solved it now, twice, but mostly it's there to fidget with instead of heading to a vast well of wasted time that's inside my phone.
I've also been leaving my phone in my office for most of the day.
One thing I've been struggling with is being angry with my kids all the time, especially in the evening. As we're back to school and to a normal routine, I've left my iPad in my office as well. No YouTube or RSS feeds or anything. Just me and a book and the chores.
I've felt more rested and reacted much more like the parent I want to be.