I thought that smart phone apps were compatible with the operating system/release and not to any particular phone. For example, an app can be apple or android, and sure you might need android 2.1 or higher, but and android app should work on any android phone, right?
Have a look at this site. They are saying that their GolfLogix app is specific to the phone. Is that normal?
I don’t know about that specific case, but Android phones can have different hardware capabilities. It’s possible the app takes advantage of specific capabilities on different models. However, if it still supports all of the models, I can’t think of a technical reason to not just put it all in one app (with some features only available on certain devices). Maybe they sell it that way to force you to re-buy it when you get a new phone?
It might also be a sales tactic to see what kind of phones people have who buy the app. If they find that a particular make/model just doesn’t sell, then they can stop writing in that bit of code that allows their app to work on that make/model’s hardware.
Another sales tactic can be purely for SEO (search engine optimization). You might type “golf course app blackberry” or “golf course app droid” into Google and having those separate pages on their site will give them a better chance of being found.