With iOS 7 set to debut in the Fall of 2013, and development timelines for apps taking anywhere from two to six months, when is the right time to develop for iOS7
This is almost an annual question for us, when do you start building apps for the latest Operating system? And while the answer all depends up your situation, the rule of thumb is that Apple users tend to adopt the newest operating systems much more rapidly than Android users. The main reason is that Apple launches their OS across the board and it is then available on all devices at the same time, where Android releases an updated OS however it needs to be configured for each handset, so it's up to each manufacturer to launch it on their respective devices.
The chart below shows the iOS user adoption rate for the latest version on iOS 6 released in February earlier this year, after just 5 days it became the most widely used version of Apple's operating system. Additionally , over 93% of all iOS users were running some version of iOS 6 at that time, compared to Android, which released it's latest operating system, Jellybean, in July of 2012, only had a 15% adoption rate 8 months later.
So with iOS users being so quick to adopt the new operating system, and development timelines taking anywhere from three to six months, even if the iOS 7 release is pushed back to late fall, it would still make sense to plan on building your application for iOS 7, which allows you to also take advantage of many of the new features that the newest OS will have.