What version of IOS to use when upload app to appstore?

I am just about to upload my first app to appstore :-)

I have tested the app on an iPhone 3G (IOS 4.2) and my iPhone 4. What version of code should i开发者_高级运维 upload and:

• If i upload 4.2 to support iPhone 3G, will that cause any problems with newer phones?

• If i upload the latest version of the code i guess iPhone 3G's will not be able to run it?

• Is it worth while to still support iPhone 3G?

Can someone please recommend me what to do?

If you upload a version that the 3G does not support, then all 3G users will not be able to download the app.

If you upload a version that is supported by 3G, then only if the users have updated their firmware will be able to use the app.

In other words, the role of thumb is: upload the one that is tested on the latest firmware, but can be launched from as many firmware version as possible.

That might mean to just upload the one that is tested on the least firmware possible, but be careful because newer firmware versions might stop supporting certain APIs that you might have used, and then all newer (potential) customers will be locked out of your app.

If i upload 4.2 to support iPhone 3G, will that cause any problems with newer phones?

No.

If i upload the latest version of the code i guess iPhone 3G's will not be able to run it?

You need to compile for arm6 in addition to arm7 architecture.

Is it worth while to still support iPhone 3G?

That's a matter of opinion. This there any requirement for you specific app that requires a iPhone 3GS?

Choosing the latest ios as the deployment version is bad idea. iOS 4.3 isn't supported by Verizon devices, which means that you will lose a big portion of US users.

I believe most of apple's apps are using "iOS 3.1" as the deployment version, and i would recommend choosing the this as the lowest supported version.

iOS 3.1 is the last version supported by the original iphone, which guarantees that all users can use your app. Note it's not enougth to just pick 3.1 as the deployment version. you will have to test it with a REAL 3.1 firmware. There are a few guides on downgrading your iphone to 3.1, which is helpful for testing (such as http://lifehacker.com/5572003/how-to-downgrade-your-iphone-3g%5Bs%5D-from-ios-4-to-ios-313)