Oh, I've made one too! http://github.com/erming/shout It's really stable (been using it for weeks without restarting) and I've even implemented a mobile interface: https://db.tt/fYTswBwO You'll find the install instructions in the README (or just `npm install shout`). No configuration required. Should take under a minute to get it running if you already have NPM. It's open source. Feel free to try it, browse the code…
How are you handling persistence tho? Straight up in-memory storage?