Zonday

Zonday is a small web game about shopping instinct. Each day it picks one product listed on Amazon in the US and shows it to every player, with its picture and name and a difficulty rating. Your job is to name the price.

You type a dollar amount and submit it. Each guess gets an arrow pointing up or down and a temperature: within 10 percent is hot, 10 to 30 percent warm, 30 to 100 percent cool, and more than double or half is cold. After your first guess the game reveals more about the item, such as its rating, review count and description, and a slider narrows to the prices that still fit your earlier guesses. For items under $300 a guess within $3 counts as correct; for dearer items you must be within 1 percent. You have six guesses.

At the end you see the real price and how far your last guess was, and you can share an emoji line of your arrows. There is also a custom challenge mode built from a specific Amazon product link, but the daily item is the one everyone plays. It suits people who like price-is-right style guessing and a quick game that turns over at midnight UTC.