Groceries, household water & electricity, and some of my basic clothing when I'm in South Africa (about 4-5 months per year). All of the above are sold at Pick'n'Pay stores and can be paid for with Lightning.

And with bitrefill: vouchers for gas, restaurants, steam (games), prepaid mobile, and other random things.

Between those two, I can cover a vast chunk of my day-to-day expenses when in South Africa. Sadly there are fewer options in the other regions we spend each year in. For now.