Michael Simon, writing for MacWorld:

Apple Watch is a conduit, not just to my iPhone, but to the world around me. While I haven’t used Digital Touch much (mostly due to the fact that I haven’t been able to convince my wife to buy one yet), the concept is central to what Apple is trying to achieve with Apple Watch. It’s not about replacing your phone or even leaving it in your pocket—it’s about using technology to stay more connected, not just through simple or multimedia messages, but through real digital contact. And that concept seems to be lost on many.

To me, intimate connectivity is a core concept of the Apple Watch that is under appreciated and, perhaps, under implemented by developers.

While there are plenty of things it doesn’t do well and likely never will—such as reading lengthy emails or swiping through voluminous photo albums—its unique form factor allows for a deeper visceral reaction to tasks I had grown accustomed to on my iPhone. The best example of this is when I receive a picture: getting tapped on my wrist to notify me that I have an incoming message and lifting my wrist to see a photo of my son appear is such a joyous interaction, it makes me linger a few seconds longer than I do when a text comes through on my phone. And I’m much more inclined to share it with the person I’m with, something I never did when my face was buried in my iPhone.

As is, the central theme of my Apple Watch is that of a notification funnel. Apps that play well in the notification space, that find a way to present a notification in a slim package that yields a more detail view if I tap it to get to the app itself, are much appreciated and most likely to stick around.

But there’s huge potential in the world beyond notifications. There’s an intimacy opportunity, a chance for Apple to bond people with their Apple Watch, that is currently implemented in the shared heartbeat, animated icons, and simple drawing app.

I’d argue that those things are signposts, simplistic showcases to give developers a taste of what is possible. Apps that offer real intimacy that allows people to feel truly connected will be the real killer apps for the Apple Watch.