The Incubation Period for iPhone Apps is Declining

A conversation with Raven Zachary at Macworld prompted me to dig into the state of new apps on the (U.S.) iTunes App store. First, I looked into the number of new apps that become available on a weekly basis. In the chart below, an app is considered new if it appears in the app store for the first time in a given week:


After a huge spike right before Christmas (close to 1,200 new apps on 12/21), the number of new apps has dropped to levels last seen in early November. (Note data for the week of Jan-11 is incomplete and covers through 1/9/2009.)

Individual apps also have release dates, which based on Apple’s recent changes to the app store, represents the date developers upload their apps to iTunes Connect. The period between the release date of an app and the date it first appears in iTunes is when Apple performs a series of undisclosed QA tests. Because it translates to a more favorable position when users sort by release date, most developers prefer this incubation period to be as short as possible.

In the graph below, I measured the MEDIAN incubation period in Sep/Oct and Nov/Dec. (Note: For each app, I used the release date published when the app first appeared on iTunes.)


There were more than 5,000 new apps introduced to the U.S. iTune store in each of the two-month periods. The categories are sorted according to the number of apps (see a related post or this chart from early December). The top 8 categories account for over 70% of all apps, with a quarter of apps coming from Games. For all but two small categories (Weather, Social Networking), the incubation period has declined. (Medical is a new category and wasn’t represented in Sep/Oct.)

While the average incubation period is declining, some developers still experience, what they consider, unnecessarily long delays. If you are an iPhone app supplier/developer, I welcome your thoughts on this subject.

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  • Great to see the new Medical category.

  • I don’t mind some incubation period I just wish it was clear what was going on during this phase. What tests are being run, how many are there and what are they? I think if developers know what Apple checks for it would help them properly prep applications for the store. We’ve had some applications accepted while apps with identical features are rejected. The process is getting better but there’s still room for improvement.

    It’s particularly problematic when we want to do a minor patch or bug fix to address a customer issue and it takes sometimes weeks. I can understand for every major release but for minor changes I wish there was a shortcut.

  • Dave

    I find your AppStore analysis very interesting. Is there a way for me to access this kind of detailed usage data as well, or is it somehow confidential?

  • If you go into iTunes Connect (the website used by developers to manage their apps) just after you received the email from Apple that your app has been approved, you can set the release date to the current date. That is extremely important since you will end up on page 1 of the “what’s new”- lists which improves sales.

    More and more developers know about this, so your data might be skewed because of that. I haven’t heard about an app or update that was approved recently that didn’t took at least 8 days, while most take longer.