I've spent cash not denominated in dollars for at least quarter of my life. It's probably much closer to half if I start counting from the point of earning my own salary.
My xe.com app is one that I still use more than most on my phone. The currencies listed change slightly depending on our location and plans. As it can deal with so many at once, changing any entry will result in the immediate conversion of all the other amounts.
It'll easily be able to gauge comparative costs of barbecued chicken in Luxor this winter. I wonder if a cooked bird will cost less than in Mexico.
I never use the Economist Magazine's 'Big Mac Index' to check price parity. In real life, the cost of a can of beer is much more important to me! If without my phone, I mentally try to compare with my informal 'Beer Index'.