Supporting older versions of an operating system interferes with introduction of new features. It makes Downcast's source code more complex and more bug prone. My decision to support only the current major version is meant to minimize bugs introduced in new versions of Downcast and reduce the time it takes to introduce new features and test new releases of Downcast.
When support is dropped for the version of the operating system you are running, you will still be able to download the most recent compatible version of Downcast (the current App Store policy) you just won't receive updates until you have upgraded to the latest version of the operating system.
Below is a table showing our currently supported versions and estimates for when support will be dropped.
|Operating System||Supported Until *|
|iOS 9.x||Fall 2016 (release of iOS 10)|
|iOS 8.2||Late December, 2015|
|Mac OS 10.11.x||Fall 2016 (release of Mac OS 10.12)|
|Mac OS 10.10||Early January, 2016|
* These dates represent the earliest time support for these operating systems will be dropped. In reality, the actual date support will be dropped will most likely be at least a few months later. For example, it is highly unlikely that support for iOS 9 would be dropped prior to iOS 10.1 being released.