If I install the 3.0 SDK, can I still make 2.0 compatible apps?

Question

I've been putting off installing the 3.0 beta SDK in case I can't make apps to target 2.0. If I install 3.0 on my computer and iPhone, will I still be able to submit apps to the app store for users with 2.0 iPhones to download? Will I have to wait until 3.0 is released to submit more apps?

Answer 1

Yes you can build 2.* apps. No you can't submit pre 3.0 apps to the app store. I can't paste the link for you since I am considered a new user, so just google "iPhone 3.0 app submit".

Answer 2

Actually, I suggest testing on OS 3.0 as it's a requirement your app doesn't break on the new OS.

"New iPhone applications will be rejected unless they are ready for Apple's forthcoming iPhone 3.0 firmware upgrade, developers have been informed."

You can still build for 2.* but I can see how testing on only one device can make you nervous. There is no way to rollback to a previous OS once 3.0 has been installed. So, if this device is also your everyday cell phone, make sure you accept possible bugs. (though I haven't heard of any seriuous problems. OS 3.0 is worth it)

As for the issue you address. Apple says:

"iPhone SDK for iPhone 3.0 can not be used for submitting iPhone OS 2.2.1 applications to the App Store."

I think they didn't express themselves too well. While technically spoken, they are right, you just have to select SDK for 2.2.1, and you're good to go.

Answer 3

You can get it free or roll back if you do not like the new software at http://www.felixbruns.de/iPod/firmware/

download then follow these steps

1.) after it downloads open itunes and plugin your ipod/iphone 2.) Hold shift if on windows (Option key on mac) and then click resotre 3.) Select the ipod file and then wait for restore 4.) you will need to set up as new ipod (it will be slow if you restore from backup

Answer 4

The installation of the 3.0 SDK mentions weaklinked frameworks --

The Xcode UI now allows you to designate a library or framework as weaklinked, to support building with newer SDKs while targeting older OS versions.

I have yet to accomplish this, but will update once figured out.

Answer 5

I understand that you wrote this a while ago and you've already accepted an answer, but I have some more advice:

1. You should install two copies of the SDK, the latest stable version (in "/Developer") and the latest beta version (in "/Developer Beta" or similar), as per these instructions.
2. For building 2.x applications, you set your "Base SDK" to 3.0 and your "iPhone OS Deployment Target" to 2.2.1, as per these instructions.