With the release of iOS 5 today, there has been some debate at my organization of which OS version we should build for in future iOS apps, iOS 4 or iOS 5. Building to accommodate multiple OS versions is more time consuming which translates to greater costs, and is not always an option. In general, we lean towards the safe side and build to accommodate more users by building for an older OS. However, this also limits what new APIs we make use of in development.
There are several determining factors that would come into play for a decision like this. One important piece of information here is how many people will be using the new OS when an app is launched. I have tried to get together some data on the adoption rate of iOS 4.0 when it first came out (links below).
Here's how it breaks down:
- 1 month after release - 50% adoption rate
- 3 months after release - 70% adoption rate
- 6 months after release - 90% adoption rate
Building for the new operating system will allow developers to access a host of new features, including storyboarding, which can greatly reduce the amount of code needed to be written in order to create an app.
So the primary question is when do you start building for iOS 5?
For the most part this is going to be on a case by case basis, but if you are just beginning the development of an application now, odds are it will take at least 3-6 months to build and launch in the App store. By that point, you’ll have between 70% and 90% adoption rates, so if you are looking to take advantage of some of the new features, then it would make sense to build for iOS5 now.
However you'll need to consider your audience, and the true benefit that building for iOS 5 brings, is missing 10%-30% highly detrimental to the success of your app?