This post is the second (or technically third) part of my series about building a WatchKit app that shows current air pollution level on the watch face. If you haven’t seen the previous parts, you might want to at least take a look at the intro.
Last time we’ve talked mostly about the general architecture of a WatchKit app. So logically it would now make the most sense to start with the main part of a watch app, the main app UI. After all, this is the only part of the app that’s required – both notifications and complications are optional if you don’t need them. This is what people normally think of when they talk about “an app”.
However… the whole thing started with me wanting to see the level of air pollution right there on the watch face, as quickly as possible. One of the three main rules of watchOS design is that apps should be glanceable, which means that you should be able to glance at the watch and see the information you need in as short time as possible, ideally within a couple of seconds at most – and a complication lets you see this information much much faster than the main app UI accessible from the app launcher.
It was also mentioned during at least one presentation that unlike on iOS, here the main UI does not need to be the most commonly used part of your app, if notifications or a complication make more sense for your use case. It can very well be something that users only fall back to sometimes when they need to see more detailed information or perform some actions.
So, why don’t we skip the view controllers for now and just build a complication?