What exactly is the Default Image for?

Question

I have finished my first iPhone app and am planning to upload it soon to the app store. One of the many questions I have encountered is the Default Image, I know how to create it, just make a screenshot in Organiser, and then use the Save as Default Image option, but what is this? Is it a splashscreen? I have looked at a lot of the apps on my iPhone that I have downloaded over time but none of them seem to have anything I could recognise as a default image, usually they just open to the main screen.

Answer 1

Hi Copernicium, and welcome to the Dev Forum!
Yes, you can think of the Default image (usually Default.png) as a splash screen and you've probably been seeing that image in most of your downloaded apps without knowing it.
The purpose of that image is to provide something other than a black screen when the app is loading. I.e. you don't bring it up with your code, the system looks for Default.png when the user touches your icon on the home page. If the file is found, the system displays that image until your app is up and running.
You're free to use almost any image you want as the Default, but the guidelines recommend an image that transitions smoothly into your first screen, or better yet an image which is identical to the first image your code brings up. When you're unaware of the transition from the default image to the application launch, that generally means the developer has done a good job.
The purpose of the +Save As Default Image...+ button in the Organizer is to make it easy to install your startup screen image as the Default. If your startup image is static it's easy. You just capture that screen, hit Save As Default and you're done. Note that if your screen capture includes the status bar, it will be masked by the real status bar when the Default image is displayed. So just two clicks in the organizer can produce and install a Default screen that's identical to the actual startup screen.
If your startup image is dynamic (e.g. the "real" splash screen), but always begins with the same view, you just need to set a breakpoint in your code so you can capture that very first image.
And yes, you'll have a better app if you add Default.png to the bundle before you upload to the Store. When last I looked, that wasn't a requirement, and there are still lots of apps that load with a black screen. But I wouldn't be surprised if Default.png is now or soon will be a requirement. It certainly helps to placate the user when your load time is anything over the absolute minimum.
Hope that answers your questions!
\- Ray