An invaluable use I’ve found for my phone’s camera is to take pictures of prices to compare with other stores and supermarkets.
There were three supermarkets very close to where I lived, and prices could vary greatly between the three. For example, a Japanese loaf (about half the length of a UK loaf and usually consisting of 6 or 8 slices – 6 slices mean they were about an inch thick each!) usually sold for ¥99 at Don Quijote (ドン・キホーテ, commonly referred to as Donki), but would sell for as much as ¥160 at Ito Yokado (イトーヨーカ堂) which is just across the street. Well, when I mean street I actually mean four lanes of very busy traffic on National Route 16 (国道16号).
£1 is about ¥125 as of writing, so ¥100 is 80 pence.
You can check out some of the loaves on sale at Ito Yokado here on their online store.
Here are some pictures I dug out of my Japanese phone.