PriceWarp

PriceWarp, by ZucchiDev, casts you as a time-travelling shopper. Each round prints a receipt with a handful of items and what they cost in one year of the last century: a Lamborghini Countach, the median new home, average monthly rent, a year of college tuition, a postage stamp. The prices come from real historical data, including the US consumer price index and the FRED database.

You move a slider to the year you think the receipt belongs to and submit. A guess within two years counts as correct. You have three guesses per receipt, and an early correct guess scores more: 5 points on the first try, 3 on the second, 1 on the third. Receipts mix easy and hard items, so a single giveaway price can anchor the whole guess.

The Daily Challenge picks its receipts from the date, so everyone plays the same ones that day. At the end you see your daily score and can copy a result with a coloured dot for each guess: green within two years, yellow within five, red further out. A streak counts the days in a row you have played. Endless mode draws random receipts for as long as you like.

It is a light way to get a feel for inflation and for how the cost of everyday things has moved, and it plays on phones and computers in the browser.