» Speaking at CocoaConf Yosemite

I’m delighted to have been asked to be one of the speakers at the next CocoaConf Yosemite. A technical conference hosted within Yosemite National Park (one of my very favorite places on earth). The conference runs from March 20 - March 23, 2017.

In case you missed it in today’s Under the Radar you can use the code UnderTheRadar to save 20% off your ticket.

Hope to see you there.

David Smith




Historical iPhone Screen Sizes

I’ve recently been curious about the overall trend in iPhone screen sizing. Both as a result of the introduction of iPhone SE and because I feel it is an important thing for app developers to understand to make better decisions about their app UIs.

Since 2013 I’ve kept a pretty detailed set of device analytics for my Audiobooks app, these are the stats that power my iOS Version Stats Page.

Included is the screen size of the device being used. While the latest summary has always been included in the bottom portion of the stats page, I’ve never really thought to look at it over time. The result turned out to be very interesting.

Here is the percent of daily sessions (30 day moving average) using each size of iPhone over the last three years. The iPhone 5 (which introduced the 4″ size) was introduced in September 2012, so around five months before I have data.

Much of the shape of this curve isn’t particularly surprising. 4.7 and 5.5″ screens have seen a steady increase in popularity since their introduction, with the 4.7″ outselling the 5.5″ at nearly a 3:1 ratio.

What did catch my eye was the impact of the iPhone SE over the last month or so. The 4.7″ curve had been steadily growing since its introduction and poised to take over as the most popular screen size. However, since the introduction of the SE the 4.7″ line has leveled out demonstrably (currently settling around 36%). This may be a short lived phenomenon, but is nevertheless very interesting to see.

From a development perspective this shows me that continuing to target my visual design around a 4″ layout continues to be a smart move. While the 3.5″ screen is essentially out-to-pasture at this point (I’d expect iOS 10 to drop support for the iPhone 4S), the 4″ layout will be with us for a long time to come.

David Smith




A Year Wearing an Apple Watch

Yesterday was the one year anniversary of the launch of the Apple Watch. It is a device that has had a profound impact on my life both personally and professionally. The Apple Watch I received on launch day is still firmly on my wrist each day (notably with barely a scratch).

I’m a bit of a numbers nut, so I had the idea to see just how much I’ve worn my watch over the last year. The result turned out to be rather striking.

I wrote a little app to dig through all the sensor data collected by the Apple Watch and work out when it was on my wrist and when it was not. I considered a “worn hour” to be any hour of the day during which a sensor sample was collected (so not necessarily worn 100% for that hour, but worn at some point during that hour).

Since receiving my watch 8,784 hours have past, during which I have worn my Apple Watch 7,277 hours. That works out to be around 83% of the time. I have worn it for at least one hour in all but just 8 days (with most of those being a week I intentionally ‘disconnected’ around Christmas).

The average hours I’ve worn it per day is 20.4. With the median a rather staggering 23.

Amusingly, you can clearly see when development of Sleep++ began in earnest in late August, when my wearing suddenly jumps to 24 hours a day.

I remember being rather skeptical of Apple’s original marketing of the Apple Watch as “our most personal device ever”, but a year later I must say that it would be a hard case to make that something that has been physically attached to me for 83% of my life is anything other than personal.

David Smith




iPad : Mac :: Digital : Film?

I love a good analogy. They clarify my thinking in a way that few things can.

While listening to this week’s Analogue a thought popped into my head about how to potentially frame the discussion around doing ‘work’ on iPads. It isn’t perfect (no analogy is) but the more I thought about it the truer it felt.

Using an iPad for work today is what professionally using a digital camera was when they were new.

While I wasn’t a professional photographer during the transition from film to digital, I was an earnest amateur. Many of the discussions today about the role that an iPad can play in a professional context remind me of the same arguments I watched on bulletin boards back then.

Professional photographers were extraordinarily proficient at using film. They had developed incredible workflows (both in camera and in darkroom) for handling film. The results they could get from film were initially objectively better than with the digital cameras of the time. Yet, over time digital overtook the industry and film is now used mostly for novelty rather than benefit.

I have no idea if the iPad (or similar devices) will ever have the same sweeping dominance that digital has over film. Though I wouldn’t be surprised if eventually it did.

David Smith