Five party games that need nothing but the phone in the middle of the table — and, if you want it, everybody else's phone too. It starts with the playground game. Everyone puts a finger on their own ring, a word is called out, and the whole table answers at once: lift your finger for yes, keep it down for no. The slow and the twitchy go red. The app opens with that game told as an illustrated story, so nobody has to be taught the rules out loud.