The product breakdown in PRINCE2 helps us scope the project. There’re various ways of defining the product breakdown: textual or graphical
If you’re a fan of mind maps, there’re numerous tools out there: free or paid; online app, mobile app or desktop app.
I’m using MindJet Maps on my iPad and bubbl.us which is an online tool. The later is flash based and may not work well on iPads. MindJet is good for capturing ideas on-the-go but is a paid tool. bubbl.us is free (can upgrade to paid account).
bubbl.us allows exporting as PNG or JPG. Paid accounts can import saved versions from their desktop to the server. It’s simple to use & does what it is suppose to do. There’re some bells & whistles but I didn’t really use them. Primarily used it for getting the product breakdown drawn.
The MindJet Maps for iPad is simple to use, learning curve is short. You can sync with Dropbox. Last time I used it was for jotting down ideas.
There’re other many other tools out there, I’m not saying that these are the best, it’s a personal preference and it does fit my needs for now.