This is a neat little diff app. Since a lot of the comments are about the lack of a demo I'll try to write about it in a bit of detail.
The workflow of this app is most similar to DiffMerge (which does have a demo) but with a better interface. You get a bunch of toolbar toggles to filter your results, two folder lists with changes in red and orphans in blue, and double-clicking a file opens the text differences in a separate new window—all like DiffMerge.
The UI is where this app shines. It's clean and well thought out, and the slew of filters it puts right on the toolbar really is excellent. Other diff apps have made me dig through menus or preference panes to toggle things like whitespace or whether I'm comparing by size, file date or file contents. A few apps have even made me dig through menus to toggle simple things like hiding identical results. This app does it all on-the-fly from the toolbar. It also lets you both drag and browse for files and has a handy progress bar while folders are scanned. Just a smart UI overall.
This app is also a true native Mac app which is pleasant. It's quick, smooth, and wonderfully small—like 3MB installed—which is impressive compared to a Java port like DeltaWalker that is 200MB installed (and clunkier).
Where this app falls a little short however is in the text comparison. It's functional but so far you can't free-form edit text (you can only copy differences left or right from what I see), it doesn't have syntax highlighting, and it only highlights whole lines of text as opposed to the particular changed words like some other apps. Hopefully the developer adds these features soon.
In the mean time, I'd highly recommend this app if you mostly compare FOLDERS. The folder view is especially clean and I found it easier to transverse folder differences with this than with DiffMerge, DeltaWalker, Araxis Merge, DiffFork and CompareMerge.
Last note: I'd like to thank the developer for still supporting OS X 10.6. It's my favourite OS and it's nice to still have a few developers looking out for me unlike cough Kaleidoscope cough.