This is a shot of the first prototype.
Followed by a shot from version 1.0, it's all evolutionary.
The prototype was portrait because at the start I had a nice design element where the puzzle would remain stationary and as the orientation of the iPad changed the interface would rotate behind the puzzle. I really liked it but I couldn't get the rotation effect to look clean enough. It started to waste a lot of time as I worked on it and I abandoned it for the current support for only the 2 landscape orientations.
I liked the the rotation design because it fitted well with the whole design. It looked simple but moved in an interesting way.