I had a play around with this having seen your post.
From what I can see, it just generates the IO setup code (unless I'm missing something.) Which to be honest, is the easiest bits of setting up the peripherals for these devices.
I guess it's of some use, but it needs to do a lot more to make it worth using. Like you can select a peripheral (say USART2), it will plonk down the pins it likes the look of on the package, then to change it you still need to pull out the datasheet and find out what other pins could be used for that peripheral. It should have a drop down listing all the alternate pins for each peripheral.
It seems like a fairly large tool that doesn't really do much.