I understand people's frustration here about a missing demo version. I kind of bought this software because I've seen it on a friend's laptop and I liked it. I could try it there, so to speak.
I also find the price of 9.99 for an app that just displays the current calendar on the desktop a little steep. But then I also think that useful utilities that make life easier and - after all - only cost about 2 cups of coffee at a restaurant... man, you really can't complain. The App Store has brought a lot of prices down significantly and now, after using the tool for some days, I think it was well worth it.
Sometimes I have so many appointments that I forget I have to go somewhere. Especially when I'm buried in work in front of my Mac (who thinks of opening the calendar all the time - and all the alarms can be super annoying). Blotter helps me remember my appointments and meetings by just displaying the next 7 days directly on my desktop. It works with synchronized calendars like Google or MobileMe, it works with my BusyCal installation, and it works with a second monitor now. I can now choose to display the calendar on the desktop of the second or third monitor.
The latest update also got rid of the dock icon (which was always open - and I don't like utilities sitting there all the time). So in the latest version a nice icon now sits in the menu bar where it belongs in my opinion.
The only thing I don't like so much is the positioning feature. One can only choose between top left, top, top right, mid left, mid, right etc. You can choose between three sizes. A very compact view, a "normal" view where I can hardly read anything from the packed calendar on my 27" iMac or a "full screen" which is again too big. Why not let the user draw the position and size of Blotter directly in the preferences instead of giving him only 9 fixed options? And then call the sizes: compact, customized (let the user draw it), and full screen. This would make much more sense and then I would also give it 5 stars :)
For me it's either too big full screen as I don't like anything tocover up my whole desktop, but normal is too small. I would like to make it a little bigger.