[Pxtl]

Ah. Yes, WP actually has built-in support for offering both a "try" and "buy" version of each app, allowing two apps to coexist as the same entry... but in practice, most follow the "free" and "pro" naming-convention and offer two separate apps.

I hadn't realized that Apple's strict curating prevented these patterns.

[MBCook]

You also can't return an app in iOS. If there is something grossly wrong you might be able to talk support into it, but in general that $5 purchase is final. I've heard that as a popular reason for the IAP model after people stopped buying apps after buying real duds for real money.