In a previous post I wrote about my initial thoughts regarding responsive Single Page Applications (SPAs). I've now done a bit of digging to find out what other folks think about this topic.
Among the blog posts I read I found Jason Grigsby's series of blog posts Responsive Design for Apps especially interesting.
In the first blog post in this series, Jason makes the case that web developers and web UI framework authors have been participating in a consensual hallucination regarding what phones and tablets and desktop computers are limited to, just as we once assumed desktop browsers were 960 pixels wide. Web UI frameworks tend to have a library of mobile widgets (e.g, jQuery Mobile) and a separate library of desktop widgets (e.g. jQuery UI). The reasoning given by framework authors is that phones and tablets and desktops are fundamentally different platforms. But what are these fundamental differences? A cellular radio? The answer isn't clear and Jason is dubious that a good answer exists.
Jason looks at the size of phones and tablets and points out that the height of the larger phones out there easily exceeds the width of the smaller tablets available. His article was published in early 2013 and since then the gap has only narrowed. In fact Jason at one point says
The small gaps that exist are either things that seem inevitable (high-dpi on large screens) or are so small to be inconsequential (does it matter that we don't have six inch displays?).
There's no clear line between phones and tablets, but what about desktops? We used to be able to assume that touch was a fundamentally distinct mode of interaction on mobile devices. However, Windows 8 and all of the touch screen desktop and laptop products that are built for it obliterates that assumption. He points to research to suggest that touchscreen desktops are not a fad. I've yet to have a chance to play with a Windows 8 touchscreen device myself but I agree. I have to believe that eventually Apple will have to catch up too.
One of the key takeaways for me from this article is that every application should be designed for touch interaction. Primarily this means making targets big enough to be easily tapped on with fingers. Because of Fitts's Law, desktop users using a mouse will also benefit because these larger targets are easier to hit.
Making desktop app responsive
In Jason's second post he looks at a typical desktop app and tries to reimagine it as a responsive web app.
One of the problems he ran into is that if you take a desktop app design and try to make it responsive, you kind of run into a brick wall. He starts making progress when he takes a mobile first strategy. He designs a version of the web app that is optimized for mobile.
Once he has an optimized mobile design, he then looks at how it maps to the desktop app and finds that it maps pretty well. That's important for a responsive web app; each screen in the mobile design needs to be able to map to a corresponding screen in the desktop design. If there isn't a mapping, that is, if the mobile design is not just a different layout compared to the desktop design, then responsive web design probably won't work.
Finally, he takes another look at the desktop design and rethinks it in terms of the mobile design. This is also an important step in evaluating if responsive web design is feasible. For the mobile design he had to compromise in some places and display less information than on the desktop design. So its important to step back and look at if these mobile design components can be used in the desktop design.
Desktop and mobile design patterns
In the third part of the Jason's series Jason looks at how desktop operating systems have been incorporating mobile design ideas. In particular he looks at Apple's Mail app on iPhone, iPad and Mac OS X.
The iPhone Mail app uses a nested doll design pattern: moving froma list of items to greater detail or sub-lists of that item. On the iPad, we see a slightly different pattern, what has been called the bento box pattern: the list of email messages is displayed on the same screen as the detail. The iPhone and iPad app actually share views (for example, mail accounts and folders listing screens).
On Mac OS X, the Mail app there shares a lot of similar design elements although it does have a different look. One could definitely imagine there being a single Mail app that runs across all Apple devices and that adapts to the available screen real estate.
To me it is a little bit of stacking the deck to use the Mail app. Because information in the Mail app is arranged hierarchically (mail accounts list, folders list, messages list), it is not too hard to design a responsive Mail app. But not all apps are so simple. Word processing apps tend to have a main content area and several controls for affecting layout and formatting. A mobile word processing app design would be quite a different design, not likely to share much with its desktop counterpart.
Also, Jason only looks at views that display lists of accounts and emails and the views that display the email itself. That is, he only considers the views related to reading email. The desktop Mail app includes formatting options and stationary options when composing email, which would take up too much real estate on mobile. This is because on mobile users are typically more interested in reading and filing and flagging and deleting email. On mobile users only need to be able to write short responses, typically. On desktop the email composing needs are very different.
Nevertheless, I think his conclusion that
responsiveness for apps is inevitable
is mostly true. Responsive web design can be a good fit for some apps and even apps that are better served by different UI designs on mobile and desktop will benefit from responsive design techniques on mobile (for example a mobile UI that responds to more real estate on a tablet versus a phone).
I find Jason's arguments compelling. The idea that phones are fundamentally different from tablets and desktops and so require different UI frameworks and separate apps is undermined by the evidence that not much actually separates these different devices in terms of technical capability.
However, one thing that I think is missing a little from the discussion is how these different devices are used and what they are used for. Yes, technically, there isn't much difference between phones and tablets and desktops except screen size. On the other hand, users on mobile devices may have different tasks in mind that they want to accomplish versus users on desktop devices. As I mentioned above regarding the Mail app example, mobile users mostly want to read and deal with email by flagging, filing, deleting etc. Composing longer or more format heavy emails are saved for when the user is at a desktop computer. Now, this isn't a big difference in goals for mobile and desktop users for this particular app, but for certain apps mobile users may have very different goals from desktop users. This needs to be kept in mind when designing optimal desktop and mobile UIs. I'll expand on this a bit in future posts, but to me this is one of the most important reasons why you might want separate mobile and desktop apps.