This is by far one of my favorite things. I have been using it for a couple of years now. No long ago I realized how accustomed I had become to it that just the though of using my old manual timer disappointed me.
Features:
You can see how many people are meditating with you (live) worldwide.
You can open an account (optional) and chat with them.
They also have the option to keep a journal.
Personal notes:
The first time I got it, I wrote the company to ask them about how to add a song (mantra) to it, and to my surprise I got a response the day after. How cool is that, eh?
Here it is. Enjoy it!