I should make it clear that the shape of the Start screen components is irrelevant here - yes, I know Microsoft keeps making a big thing of them being square, and is matching the whole UI in the big Windows 8 transition that's currently causing controversy in desktop circles* - what's important is the density, flexibility and activity.
* for what it's worth, Windows 8's UI makes a lot of sense on tablets, but is a stretch too far on non-touch laptops - but that's just my tuppence worth....
You see, I've been bouncing around between half a dozen different smartphone UIs and so have had plenty of opportunity to get to grips with the pros and cons of each UI:
- Android - there's certainly massive customisability here, with variously shaped live widgets, a dock of shortcuts, app folders if needed, a swipe down notifications pane. But there are also usability issues in comparison to Windows Phone. For starters, most people need at least three (and often four or five or more) homescreens to fit in all the bits and pieces they want, then they have to remember which thing is where. Then you swipe down the notifications, only to discover that you're getting quite a few items there from things you weren't that interested in, in the first place. Each has to be side swiped away in order for you to be left with the notifications you really wanted.
Switching between applications can also be done using the 'recent apps' list, but this contains items in the order you used them, even if they're now closed again. And navigating this rich list is time consuming - it's faster to find the shortcut or app in the main app menu.
Even Google Now, clever though it is, has started to introduce stuff that all has to be swiped away, and I can't help but feel that the whole 'notifications' culture isn't becoming too all-consuming. Do we really need information pushed from every single source?
Swipe, swipe, swipe....
- iOS - Apple's iPhone interface has evolved a little since 2007, but not hugely. The main swipeable pages of icons and now icon folder remain - almost all of which are completely static. There's now a swipe down calendar and notifications pane, Android-style, but I still find getting around iOS requires more taps and swipes than in other mobile OS.
In fairness, the regularly spaced iOS front page has up to 24 application shortcuts - some of which may be to folders and thus a lot more can be only one extra tap away - so provided you've spent the time to customise the order of all your icons/folders, it's possibly to make iOS pretty productive.
Switching between 'running' applications is similar to on Android, using in this case the home button double press, but again it's quite time consuming swiping left and right to find the app you want among the last 80 things you ran since a week last Tuesday....
- Blackberry OS 10 - the idea here is that your main front screen is composed of thumbnail views of (up to) the last eight applications you ran/are running. It's a nice approach (and mirrored to a degree by Jolla's Sailfish OS, which I've also played with at length), but it suffers from usability problems in that the thumbnails often look very different for each application, depending on what you were last doing in it - plus the actual positions of the thumbnails vary from moment to moment, so you've got to keep playing 'hunt the thumbnail'.
Your main source for notifications is the 'hub' view, off to the left and peekable from anywhere with a gesture. The system works quite well, but it's easy for this to get cluttered and my heart often sank as I headed there, to be faced with a barrage of Twitter mentions and Facebook events. Yes, it's possible to work towards filtering and customising this view, but it's not trivial.
- Symbian - it's worth mentioning Nokia's 'old' smartphone OS here too, in that in some ways it represented the best of all worlds. At least, it used to - the classic Nokia N97 (for all its other faults) interface, with three pages of six fixed size widgets each, any of which could be set to a panel of four application shortcuts, backed up by an application menu that could be completely and utterly customised, still represents for many people an almost perfect front end in terms of notifications and information.
Sadly, the temptation to enlarge widgets and generally tinker with things got the better of the Symbian folk at Nokia - and then the company dropped the OS altogether, making the comparisons with Windows Phone somewhat moot...
Against this background of UI whinges from yours truly, there is, I contend, the relative wonder that is a well configured Windows Phone 8 Start screen, modelled here by Rafe on his Lumia 1520:
Density
Again, don't fixate on the square nature of the elements. Add in imaginary rounded corners if you must - though don't get sued by Apple in the process! But the square interface does represent perfect efficiency in terms of layout. In Rafe's layout above there are 24 applications or widgets ('live tiles' in Microsoft parlance) and as you can see from the photo, Rafe wasn't even trying. In turns out, if you do the maths, that you can fit 60, repeat SIXTY, application shortcuts on a single Windows Phone Start screen without swiping at all. Add in another screen's full and you double that. In a real world layout like Rafe's above, add in about 1.5x extra screens full and you've got 60 or 70 items, some with large rich live tiles with active content, some with less and some just shortcuts.
Flexibility
The sheer possible density of shortcuts and information also gives rise to extra flexibility. Even more so than Android, every person's Start screen is likely to be totally different to every other's. And you can tweak positioning and tile sizes without having to remove them and re-add them (e.g. picking a different widget size à la Android). Plus I'd mention that the 'flipping' (animating) of live tiles means that they can shown two different sets of relevant information each, if programmed to do so - so in many cases you really do get two for the price of one (e.g. in weather forecasts, with today vs the rest of the week).
Activity
Finally, and possibly controversially, given the clamour for a notifications system in Windows Phone 8.1, there's the numeration of new 'things' on many live tiles. The original concept for the UI was that you could take in the status of your smartphone/life with a single glance ("Two new app updated, will look at them later, five new emails, will check them soon, no Twitter DMs, ooh, a new SMS, will just tap through to see that one" and so on. Plus the information delivered by the live tiles themselves, in terms of upcoming appointments, weather, stock prices, flight delays, etc.
(The 'recent apps' list on Windows Phone is - famously - limited to seven thumbnails - this is often quoted as limiting, though in view of what I complained at above with iOS and Android, being only able to go back seven apps does completely get round the 'swiping and swiping until you get to what you wanted' issue - either the app is there in the first couple of screen's worth or it's not there at all!)
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In short, the single Start screen which often doesn't need swiping at all, the notifications which just appear and thus don't need to be swiped down and then swiped away, plus the sheer density of application shortcuts/information, all mean that - utterly to my amazement, as a long time 'Microsoft doesn't do good UI design' thinker - I'm more at home now on Windows Phone's Start screen than in any other smartphone OS front end.
Is it just me? Have I been drinking too much Redmond kool-aid? Or do you think I'm making valid points about Windows Phone's Start screen UI and that it's quite possibly underrated?