Need Help With WatchKit

On watchOS 2 and iOS 9, you can use the new WatchConnectivity framework to communicate between your iPhone and Apple Watch apps.

on watchkit you can use the "openParentApplication" from the interface controller and in appDelegate you call handleWatchkitExtensionRequest. A couple of important points:

I found I needed to open a background task at the beginning of handleWatchkitExtensionRequest and close it after my reply. This may have been due to the fact I was making an http request in the handle ExtentionRequest.

Note that if you're doing an async request (such as getting data from the internet) you need to do the reply within the response handling of the async request.

One thing I forgot...I told my app to allow background processes. (Background modes under capabilities) I'm not 100% sure this is necessary.

I think that the openParentApplication() is the fallback you would use on Watchkit 1.0 / iOS 8.x deployments. For the Watchkit 2.0 / iOS 9.x deployments, the WatchConnectivity framework is the way to go. I'm not sure how to implement the "if #available()" tests though, since it appears that Watchkit 1.0 SDK is missing from Xcode 7 currently. Additionally, we'd probably have to assume that the user will be "forced" to upgrade both iOS (to 9.x) and Watch OS (to 2.x) simultaneously when the production versions are rolled out, so we can use some variant of "if #available(iOS 9.0, Watchkit 2.0, *)" for our tests.

Any thoughts on writing Watchkit 2.0 apps that also run on WK 1.0? Or just assume we push a new version, and keep a couple of branches (yuck!)?

[edit] It appears that you can add a WatchKit 1.0 target to the project, and then share some files between the two variants. Now, I still need to find out how to get WatchKit 1.0 sdk into Xcode 7...