A common thread between the popular iPhone mobile device and Facebook social networking services are the apps that can run on either platform. But according to mobile analytics firm Flurry, the iPhone is proving the more popular platform for applications, with twice as many available apps than Facebook despite launching a year later and with fewer users.

According to Flurry’s Smartphone Industry Pulse for February—a monthly update on the data and trends Flurry picks up in the course of its research—the iPhone generated more than 140,000 apps in its first 18 months compared to the 60,000 the company estimates Facebook generated in the same number of months.

Flurry says the reason the iPhone has prevailed is because it offers developers a better path to revenues than Facebook. Going forward, the continued growth of the platform will start to create tension between smaller developers and the larger brands expected to compete with them for attention.

From the study:

"Despite the fact that the App Store is now maturing, reaching its two year anniversary this summer, we are encouraged that native iPhone application developers are still relevant, representing 20% of the heritage pie, the second largest category. This means that the barrier to entry is still low enough for start-ups to enter and innovation to flourish. However, those days may be numbered as "discoverability" has become a significant issue, and now "marketing muscle" is starting to count more in the App Store. This favors brands and larger companies with resources to spend their way in. We are seeing signs that big brands are becoming more active, now perceiving that the iPhone has reached critical mass. With iPhone and iPod Touch now exceeding 70 million units world-wide, we expect 2010 to be the year of brands entering the iPhone. Going forward, we will especially see more movement by established brands from media, retail and CPG. In particular, traditional media (News, Books, TV, Film, Music, etc.) growth will accelerate aggressively with the introduction of the iPad."