Hay Day is a freemium mobile farming game developed and published by Supercell.

[1] According to a 2013 report, Supercell earned $30 million a month from Hay Day and Clash of Clans.

[2][3] In 2013, Hay Day was the fourth highest game in revenue generated, with a total of over 1.2 billion dollars in gross income by the end of 2013.

[4] Hay Day is a farming simulation game where players can grow crops and feed livestock.

When they get enough experience points, they go up a level in the game, which unlocks more features, such as new crops, goods and livestock.