Via Fred Wilson, here's a look at the 25 most popular mobile apps as of mid-2015, a list that you'll see is utterly dominated by Google, Facebook, and Apple:
As Wilson notes, "There isn’t a single 'startup' on that list and the youngest company on that list is Snapchat which is now over four years old." In other words, we've experienced a closing of the app frontier and entered a phase of consolidation.
But another theme I would note is that this chart calls into question two bits of conventional wisdom that currently exist in the technology press. One is that the strength of Apple's iPhone franchise fundamentally rests on the strength of the app ecosystem — developers develop for iOS because iOS has the best customers, and high-end buyers flock to iOS because it has the richest app ecosystem. The second bit of CW is that this means Apple needs to cultivate a similar virtuous circle between users and developers to succeed with products like iPads, Apple TV, and Apple Watch. In other words, for its new products to succeed, Apple needs to do more to improve its strained relationship with independent developers.
From this chart, though, it seems maybe Apple's relationship with independent developers is strained because Apple can see that those developers aren't as important as they think they are. The main thing people want to do with their mobile devices is access services from Facebook and Google, meaning that the important thing for Apple to manage is the delicate relationship between giant companies that compete with each other while also being codependent.