In recent times. on the things that 99% of the people cannot do without are their cell phones. They carry it everywhere, read their book in them, browse the world news fro it as well as talk to their contacts through it.
But there is actually more that you could do with your phone. It can actually act as a record book of sort and all you actually have to do is use its camera function to give you a few easy hack for your life.
One of the things that you can do with you phone is ofcourse to take pictures of your fridge and pantry before you go shopping for groceries in place of making a whole list, since a single photo would tell you what you need and what you might have excess of.