In the early days of iOS app development, there was one screen size to worry about. A simple 3.5-inch screen at 320x240 pixels. The retina display in the iPhone 4 was the first added complexity to designing iOS apps, as the resolution doubled to 640x480 pixels, but stayed at that 3.5-inch screen.
The original iPad is what really shook things up. A much larger screen at 9.7-inches, and a different aspect ratio with 1024x768 pixels. While an existing iPhone app could be run on it, it wasn't pretty. Apple's solution was to have either apps that ran only on the iPad, or to have what they called universal apps, where the iPhone and iPad interfaces were bundled into a single app.
This was a great opportunity for app makers to reimagine their apps for a new class of device, however, those who wanted to be first to the iPad only had weeks to completely redesign their apps for a device they had not yet held.
Everything was experimental.
Naturally, this was a little risky for app makers. I recall many of my favorite apps coming to iPad as separate apps from their iPhone counterparts. It made sense, as no one knew whether the iPad would be a runaway success1, or if would be derided as "just a giant iPhone."2
As time has gone on and the iPad has found its place in the world, many apps that had separate releases for iPhone and iPad released major updates as universal apps.
There were inevitably some apps which targeted the iPad first. There is even a site dedicated to celebrating apps that ship for iPad first, though it doesn't appear to have been updated recently. One app that comes to the forefront of my mind is iA Writer. The iPad app shipped first, and an iPhone interface was added later.
These days I can't say I see too many apps debuting as iPad first. Most are universal at launch, or start out on the iPhone first.
What is more interesting to me is not the initial launch, but rather the order in which features are added. For the rest of this article, I want to focus on universal apps.
I prefer universal apps. I switch between my iPhone and iPad constantly, however the mood or situation strikes me. One thing I enjoy is that when an app is universal, it is simply there for me no matter which of the two devices I pick up. This leaves me with a certain expectation that the feature set between the iPad version and iPhone version of a universal app should be pretty on par.
Unfortunately that rarely seems to be the case. Too often these days I see universal apps gain new features and designs and layouts on the iPhone first, and the iPad side of it just lags behind.
Let's call out some apps that do this. Twitter is one of the biggest offenders. They consistently roll out new features to the iPhone first, and maybe someday bring them to the iPad side. I've seen Twitter drastically overhaul the interface of the iPhone before, and leave the iPad interface to languish for months.
Facebook is another one. They usually roll out design and feature updates to iPhone first, and iPad sometime later.
Even some apps I love dearly do this. Day One, as much as it pains me to say, has done this. They will roll out a feature on iPhone, then bring it to iPad. Thankfully, they are usually quick to bring things back into feature parity, but sometimes I'd rather just wait a couple extra weeks for a truly complete update to a universal app, rather than a staggered rollout.
I don't think this practice would bother me so much if the app in question were not universal. To me, universal does not just convey that I pay once to install on both device types. It conveys that the two interfaces should be maintained in parity.
Apps that have done this right the past couple years have been Twitterrific, Paprika, Byword, 1Password 3, and others. These apps continually release feature parity as universal apps across the two interfaces, without feeling like the iPad version is "just a bigger version of the iPhone".
I am delighted that many smaller development companies sweat the details to make sure their universal apps always feel universal in every way. My fear, though, is that some of the bigger companies like Twitter and Facebook are setting a trend where the iPad is an afterthought for universal apps, and that the iPad will become a second class citizen in app development, instead of a joint-heir with the iPhone.