Re: I can do that without an app!
"Is it that difficult to have a piece of paper in your pocket?"
Yes..... and no. If I'm just heading over to the hardware store for a few things, I'll often have my list on a piece of paper. Where the list on the phone comes in handy is when I see I'm running low on something such as sugar. I put it on the list. The same goes for hardware bits and bobs. It's the things I'll buy the next time I'm at the store so I don't forget and have to drive miles if I really need it. I nearly always will have the phone with me since I work in the field which means that bit of paper with my shopping list won't be left stuck to the fridge. It works for me, maybe it will work for others to do it the same way. I could do without a list on the phone. I could even do without the phone, but I expect my customers aren't going to go the same way and if they can't call me, they'll will call somebody else.
Since I'm in the field about half the time for work, if I happen to be near a store that has something I need, I can stop and buy it and see if there is anything else I can get at the same time. Much of the time, it's hardware. I always have projects in mind and I try to keep a stock of things I use all of the time such as screws. If I use up what I have, I like to get more before I need them again so it's not a special trip to the local store where they can be much more expensive if they are in stock. Some projects need items from a commercial supply shop so it makes sense to me to visit them when I'm in the area even if that project isn't top priority. There are also times when I need a truck so if I have one for a job, I'll look at my lists to see if I can piggyback things I need for the house.
My approach is really one of having a think if a computer/software approach is adding any value. If I have to trade privacy to get rid of a paper list, no, I don't see value in that. If I'm not trading privacy AND it's making sure that when I'm at the warehouse grocery 45 miles away I get everything I need, the added efficiency does have value for me.
If somebody nicks my phone, they'll find it wasn't worth the effort. I don't do anything financial or personally sensitive on it, it won't call Nigeria and the phone itself is worth less than $100 (currently a gen or two back Nokia). It would be a giant PIA, but not crushing. I haven't heard of anybody nicking a phone directly from somebody in a supermarket. The latest iPhone might be a target, but that's not anything I'd own.