Marco Arment linked to a blog post and commented that paid iOS apps are not dead:
In most categories, if you either solve a new problem that a lot of people have, or solve an old problem in a new and better way, you can sell a paid app today just as well as you could in 2008. In fact, the market is much bigger now. But, as with any maturing market, you’ll need to do more to get noticed since so many problems have already been solved so well.
Bull, unless of course you make games. Apps — of the productivity persuasion — are indeed dead. If you can’t make a living, what’s the use. In 1999 Palm sold 6 million units. Infinity Softworks, in its first full year of sales, sold $200,000 worth of software. That means we made about $0.03/device sold. I was breakeven and made a living for myself. In 2009, our first full year of selling iPhone apps, Apple sold 20 million units. We brought to the table a decade of customers moving to iOS, an App Store in its infancy (less competition), and an app far more capable then anything I wrote in 1999. We made about $50,000, or a very pathetic $0.0025 per device sold. Yes we have had more success since mostly because we were involved with the iPad launch, but not one of these years has approached our peak Palm years. (1999 was not our peak.)
In other words, not only is there no market for paid (Android and iOS productivity) apps , there probably never really was. The occasional hit comes and goes, but the peak is too short lived to sustain a reasonable productivity app. A few of those early apps (like Instapaper) had staying power, but there were precious few of them, and far less than in the Palm/Windows Mobile days, especially when you consider how many more devices are being sold now than before.
 I want to be very clear here. I am talking about one-time purchase productivity apps, the kind where you buy the app and use it. In the old days we sold those apps and then sold upgrades. I believe the market for productivity tools is moving to subscriptions.