There is a concern by many app developers that the app market may be getting too saturated with apps. The amount of apps in the Apple App Store in December 2009 was 160,000, that total grew to over 8 times that to be at 1.3 million apps by September 2014. In December 2009 the Google Play Store had 20,000 apps and has since seen a much larger growth to over 1.4 million apps. With so many apps available it isn't surprising that people think that the app market may be over-saturated. The answer to the question of whether the app market is over saturated is both yes and no.
A good portion of the apps on the app store have been apps like Fart Machine, soundboards, and other apps which may be considered nuisance apps. They may entertain kids but they don't really do anything useful. With so many different options for your latest fart machine app there is definitely an over saturation in this area. Apple has realized this to and will not allow any more nuisance apps. Google Play on the other hand has a lot less restrictions on what can and can't be posted on their store.
Another area that is over saturated is the pay to win or pay to play game area. There are a wide range of pay to win games available on the app stores. These games are designed to get people hooked to the point to where they will pay to win. Not only do gamers find these apps frustrating, there are too many options. Everything from farming simulators to castle builders to city builders and more.
Other than those two areas the app market is not over saturated. There are apps for everything that is currently imaginable but every day someone imagines a new area for apps. People will also always like variations on apps, it is what has built the market to the number of apps it is at today. Both app stores also take their time removing outdated or apps that are no longer working so the numbers mentioned above may be inflated beyond that of the number of apps that are actually working. The simplest answer to the question is that both app markets could use trimming to reduce the number of nuisance apps and pay to play apps.