Skyhook Wireless has done a very interesting analysis that seeks to reveal how many of the thousands of location-enabled apps are available across multiple smartphone platforms. Curiously there are only 43 it turns out. According to the report:

There are nearly 6,000 iPhone location apps, 900 on Android and 300 on BlackBerry. Only 43 of these apps are available in all three stores. Of these, only six are paid. Each of these six paid apps, detailed on the next page, has a distinct per-platform price point. These apps are always significantly more expensive on Blackberry than the counterpart versions of the same paid app on iPhone and Android. For example, Wikiango is offered for free on the iPhone and for $19.99 on Blackberry.

The most fascinating aspect of this, beyond the lack of overlap, is variable pricing for the same apps. BlackBerry users are getting stuck, it would appear, with much higher prices for the same apps. Here are three "case stuides" from Skyhook showing these price differences by platform:

As shown above, there's a $10 difference between the cost of the Zagat app on the iPhone/Android ($9.99) and BlackBerry ($19.99). Why is that? It may have to do with the demographics of the RIM user population and its legacy "enterprise user" base. Developers may simply believe they can charge more. There may be another explanation, but it's not evident.

More generally Skyhook also shows a comparison of free vs. paid apps across the three platforms. In the aggregate the iPhone has the most paid LBS apps, which is partly a function of having more apps in general: