Whether it's revisionist history or not, there were later claims that Steve Jobs knew they couldn't have a native platform ready when the iPhone was first announced so they stalled for time to a) get the App Store ready and b) see what types of app ideas were popular to get those platform APIs finalized. The interim solution was web apps with recommendations to look at the Dashboard APIs in Mac OS X (which were basically web apps).
I don’t know anything about an AppStore alternative but I do seem to recall a presentation or two mentioning using Dashboard widgets as a route for development.
After the iPhone but before the App Store I was at a developer event in NYC. If you comb the internet for the developer talk at that time you can see it alluded to. In fact Apple still insists that the web is a perfectly good place for these not App Store suitable.
