I believe that all these appliances need to be turned off once a day.
I leave my PC open all day and my I pad is on most of the time and only gets physically turned off if there is a problem, which is rare.
I also turn off my mobile at night but that is mainly because it is next to my bed, and it would wake me each time I got a message, or email, and even turning off the sound it would vibrate. Besides which, I do not want messages, texts etc while I am asleep.
I technician once told me that PC should not be turned on and off during the day but should be turned off during the night.