I reciently bought a new mac, with new version of xcode, which (I heard) only works with latest iPhone SDK. So, if I build my app with this will it still work on a device with older OS (i.e. 2.2.1) ?

Nope. Not sure if you can easily install the old SDK without already having it installed either.

This is pretty much the main reason I haven't upgraded to Snow Leopard yet.
It would be really useful if we could get some stats on iPod touch users upgrading to 3.x.

monteboyd Wrote:This is pretty much the main reason I haven't upgraded to Snow Leopard yet.
It would be really useful if we could get some stats on iPod touch users upgrading to 3.x.

I've seen stats as low as: 1% of Touch users have upgraded to 3.x. I've also seen stats as high as one guy saying like 85% of his users were 3.x, although he didn't specify if that was Touch or if there were other factors that may have contributed to that.

I'm giving up on 2.x for three reasons:
1) in app purchase is only available with 3.x
2) I expect 3.x will be free soon for Touch users, now that Apple got the feds to relax SOX accounting rules
3) I doubt anyone who isn't willing to pay $5 for an OS upgrade would be willing to spend anything on my game(s)/products

monteboyd: supposedly you can still set your deployment target to 2.x, even when building against 3.x. As of a couple weeks ago, Apple even allows you to use Store Kit but still target 2.x and they won't reject your app. This means you still can't touch the store kit code from 2.x or it'll crash, so you need to do runtime checks to avoid using store kit on 2.x, but the binary will still run otherwise on 2.x devices. See this link on deployment targets.

Thanks AnotherJake, that's really useful to know!

AnotherJake Wrote:supposedly you can still set your deployment target to 2.x, even when building against 3.x.

Yup - been doing this on Snow Leopard for a while, but make sure to compile with GCC 4.0 and test on an actual 2.x device (or suffer the nasty consequences). I also found out that Apple also won't accept universal binaries with a deployment target set to 2.x, even though they worked just fine on my 2.x device.

Thanks for the confirmation and the tips Frank!

So, then it's possible, but Apple will reject it.
Do Apple allow 2.2.1 apps built with the 2.2.1 SDK?

captainfreedom Wrote:So, then it's possible, but Apple will reject it.
Do Apple allow 2.2.1 apps built with the 2.2.1 SDK?

I just submitted one about 2 days ago... So I sure hope so.

Ok, thanks for the answers