Windows Phone navigation and task switching: Back means back
I found this year-old post by Peter Torr on MSDN for developers that outlines Microsoft's thinking behind the Back button's intended behavior. Some are complaining about Windows Phone's multitasking behavior and are suggesting that apps should resume from the Start screen. My thinking is that allowing so would break the Back button's functionality within the Windows Phone navigation model which includes, among others, deep-linked secondary tiles.
Note how the post emphasizes that Windows Phone's built-in apps follow the guidelines. Pinned people tiles, pinned artists, pinned places. All will go back to the Start screen if the back button is pressed. The Back button won't bring you up within the people hub, music hub, or maps hub respectively. Back means back. The blog post is suggesting that third-party developers follow the same behavior. A quick check and I found that apps like Facebook, Foursquare, Nokia Music, and 4th and Mayor follow this suggested behavior, while Flixster and Nokia Maps don't. So it seems that unfortunately, compliance with the guidelines aren't checked during app certification.
Many are saying that Windows Phone should just follow how other platforms do things. Maybe they are right. In any case, I believe this paragraph from the blog post is quite apt:
Windows Phone has a different overall user experience than iOS or Android or Symbian or BlackBerry (or any other OS for that matter). The way a user interacts with your application on another platform may not translate well to how they would interact with your application on Windows Phone. And whilst it might seem logical to say “users who move from other OSes to Windows Phone will be confused if apps work differently”, remember that the vast majority of smart phone purchases in the future will come not from people switching from one OS to another, but from people who have never owned a smartphone before and, in many cases, have never owned a PC before either. These are your future customers and they have no pre-conceived notions of how apps “should” or “should not” work; they will simply notice which apps do or do not work well on the phone they choose to buy. In other words, familiarity with the behaviour of other smartphone OSes is not a good excuse for building poor Windows Phone experiences.
What I think the blog post shows is that there are some carefully thought-out decisions behind how Windows Phone works.
I do think the current task switcher can be improved on. I think that a simple grid view of in-memory apps as the first screen of the task switcher is better than the single-card view. That can show most or all in-memory apps at a glance, and quickly accessible. They can make the cards accessible by swiping left, or via semantic zoom. Additionally, faster launching of apps from the Start screen may slightly mitigate the desire for resuming from Start screen.