Can an app with deployment target iOS 8.3 run on iOS 8.2?

Question

I am about to release my first app. In Xcode, I set the deployment target as 8.3 . When testing my app with third party testing platform, it looks like my app can't been installed on a device running iOS 8.2 . So I have the following questions about the iOS compatibility:

1. Can iOS 7 app running on iOS 8 device?
2. Can iOS 8 app running on iOS 7 device?
3. Can iOS 8.2 app running on iOS 8.3 device?
4. Can iOS 8.3 app running on iOS 8.2 device?
5. How to make the app compatible to as many iOS versions as possible?

Answer 1

Apple is very selective with compatibility, mainly because it makes them more money to have strict compatibility rules since people will just buy new stuff. But anyhow, anything made for iOS 8.xxx will work for that version and later but has a slim chance of working for anything below that xxx version. So your deployment target was 8.3 so you should only completely be able to use it for versions 8.3 and later.

The xxx is the minimum required version of iOS a device is running. You may be able to change the deployment target to something earlier as long as you did not use 8.3 specific features to the point of not being able to change the target without redoing your entire app or at least removing those specific features.

Answer 2

I. An app compiled for iOS 7 will run (most likely) on iOS 8, but expect to see a few glitches here and there.

II. An app compiled with iOS 8 SDK will run on iOS 7 if the deployment target includes the latter (and you take into account API diffs).

III. Same as I.

IV. Same as II.

V. Make sure you compile the app with the latest SDK, and set a low deployment target. To be honest, there's no need going below iOS 7 these days.

Answer 3

Kindly find my inline answer to your question,

Can iOS 7 app running on iOS 8 device?

YES

Can iOS 8 app running on iOS 7 device?

Yes, If you have set deployment target to 7.0, but better you review it once before publishing on App Store. API change might affect. Major change is size class which was introduced in 8.0

Can iOS 8.2 app running on iOS 8.3 device?

Yes

Can iOS 8.3 app running on iOS 8.2 device?

Yes, If you have set deployment target to 8.2, but better you review it once before publishing on App Store.

How to make the app compatible to as many iOS versions as possible?

Set the deployment target of your app to 7.0 & It will cover majority of the devices/users.

Set iOS Install base in below figure(Updated on 25th May 2015),