When Kyle and I decided to make Begin free, the app wasn’t really designed to be free. So Kyle spent a lot of time re-working Begin so that it was better suited as a free+IAP app.
Instead of the IAP just being themes, we added a ton of stuff and reworded the IAP to “Extend”. I don’t like “pro” labeling, especially for Begin as it is not, and never will be, by design a “pro” app. So if you want to pay us $0.99 you get to extend the feature set of Begin.
Either way, the app is still damned useful. I use it everyday.
Really though, the app is free and the icon is fantastic — no reason not to download it and check it out.