You Say First
You-say-first is a web application to play ad-hoc games where all players have to submit their moves at the same time (e.g. rock-paper-scissors, diplomacy). Here, you can create a room (just enter any name that you want), share the address with your friends and start playing. You can enter your move, and as soon as everyone ticks the ‘Final’ field, the moves are shown to everyone.
You can see it in action at http://you-say-first.nomeata.de/
Especially the UI needs more love. Pull requests welcome!