I use note apps for example instead of paying for paper and Pens that I'd be forever using. I find it so much easier to quickly type a note up on there instead of having to carry an additional notepad and pen along with my phone. I also tend to play "board game" or "card game" type games on my phone instead of buying board games or cards nowadays as well. I'm not sure if I'd even play them still if it wasn't for having the phone to play them on.
Personally, my laptop has replaced my notebooks in quite a bit of subjects as it is relatively easier to just write down everything here and access it much more easily later on. Another thing it replaced was newspapers. Despite not replacing it for me, it's become easier for people to just read the news online instead of paying for it. Plus, Skype help replace phone calls as they can now be done for free.
I second the not point. I find it so much neater and so much more convenient to use the note app instead of stressing to find pen and paper. Then you have to put the note somewhere where you will not lose it, which does not always work out. So that saves money. also, compass applications have saved us money too.
