I had been looking for quite a while for such a software for Mac so I jumped on it and went straight to the paid version ($9.99), believing I was going to get all the features enabling the creation of boards such as those presented on the demo pix.
What I have received is the basic version of the software : no rotation of the pictures or tweaking of their transparency, no fun pins. The pictures just sit straight on the board, which is kind of boring.
I went back to the developer's site and now realize that there is a pro version, not yet available though. I suppose this is the one worth having for full functionality.
As a conclusion, this could be a very nice little software with added features. My suggestion is to stick to the free version until the pro version is available.