Will Retina-ready iPad apps explode in size? Not necessarily

In case you hadn't heard, the sky is falling.

iPad apps as we've known them are about to get super-sized and are now on a collision course with whatever space you thought you had on your iPad--old or new. Early evidence pointing in that direction comes from Apple's own applications, which were all updated last week to coincide with its new tablet, and became considerably larger as a result.

As my colleague Jason Parker detailed earlier this week, Pages--the word processor app in Apple's iOS iWork suite--jumped from 95MB to 269MB, while Numbers--Apple's spreadsheet app--increased from 109MB to 283MB. Yesterday, an extended hands-on with the new tablet from Vietnam-based blog Tinhte came with additional numbers, mainly that iMovie has ballooned from 70MB to 404MB.

Here's the thing though: while it's easy to apply a multiplier onto the size of these apps and guesstimate it for any app that's out there right now, developers CNET spoke to said it's not that clear cut. Like a snowflake, each piece of software is different, and it all comes down to the content that gets packed in. Things like videos, music, and high-quality image and texture assets that are included in applications could be getting upgraded, but not all those things are equal in terms of the impact they have in size.

In the case of the updated iMovie app, it's a big mix of all these components. While things like buttons, knobs, and interface elements have gotten the "Retina" treatment, a big chunk of that size increase can be attributed to media Apple has added within the app. That includes the new trailers feature, which lets people make Hollywood-style movie trailers using footage they've shot.

As part of the new feature (which was picked apart for size by a "="" rel="follow" target="_self">Reddit commenter), Apple included 17 audio tracks, most about 2 MB in size and running about a minute. That's basically half a music album's worth of data that wasn't there before. Apple also included preview movies a few seconds long--but even these short videos can take between 300KB to 600KB each. There are 20 of them per trailer type, and there are nine types of trailers. All told it's a little more than 100MB of content, which is bigger than the entire app was in its last incarnation.

With Pages, Apple didn't tack on any new whiz-bang feature that's brought on audio or video files. The simple truth of the matter is that it's just a big app, with more than 1,000 image assets that needed Retina-ready counterparts, all of which come in at a bigger size and are an addition to the old ones. Examples like this are where some of the fear about bulging file sizes is warranted, since users on older devices aren't getting the advantage of these higher-resolution components, but will have to download them nonetheless.

Something else to consider is that many potentially bloat-inducing culprits, including standard app buttons and background textures, are pre-installed on the device, so apps often don't need their own. However, some developers create their own icons and buttons, which can add to an app's overall size. That includes the popular, and already updated Tweetbot app for Twitter, which has its own set of icons and visual features it brings along for the ride.

How big can apps get?
One consideration is that Apple has a firm limit on how big apps can be, which is 2GB per Apple's iTunes Connect--the system developers submit their software through. For something like the entry-level, 16GB iPad that works out to about seven applications given the space you're left with right out of the box.

Do any apps even come close to this per app barrier already? Yes, but they're games. EA's FIFA '11 and '12 editions both are more than a 1GB; the larger '11 version is 1.26GB. There's also Epic's Infinity Blade 2, which is 791 MB, and two of Gameloft's Modern Combat titles break the gigabyte barrier.

How big will these particular games get once they've been given a polish for Apple's new device? That remains unclear. Once again it depends largely on how much of that bulk are game assets the need double-sized versions, and if developers come up with any workarounds to make their apps take up less space.

One place to look in the meantime are the applications that have already been updated for the new tablet. Here's a chart of the ones that are not new apps, and how they were affected in the jump: