ChallengeMe: Social Game Application in which friends challenge each other.
https://apps.apple.com/ru/app/challengeme-%D1%81%D0%BE%D1%86%D0%B8%D0%B0%D0%BB%D1%8C%D0%BD%D0%B0%D1%8F-%D0%B8%D0%B3%D1%80%D0%B0/id1469834548
