http://www.businessinsider.com/apple-watch-apps-will-improve-in-two-weeks-2015-4:
Most third-party apps for the Apple Watch have been created by developers that have yet to actually try out a physical Apple Watch — and that means most third-party apps haven’t actually been tested on the device itself.Once developers get their watches, they’re going to make a bunch of improvements quickly. Developing games for the Apple Watch has been a unique challenge. With the iPad, you could at least understand how your app would work because the apps were running on the iPad itself. With the Apple Watch, the delay from tapping the Apple Watch’s screen, to processing on the iPhone, to updating the screen from iPhone to Apple Watch, is something that was simulated in the iOS Simulator but not exactly understood and felt until you used the real Apple Watch.