Non-English default language for iOS App?

I am developing an app for a client in Europe. I am an English-speaker in the US. Our app is going to support a number of languages, but not English. I have all the strings in our app in translated Localized.strings files, set up correctly for the different languages, and they all work fine when the device is set to the correct language (device's language is German = app is correctly localized for German).

There is a problem when the device is not set to one of the languages we support, for example, on my phone which is set to English. We want the phone to fall back to German in cases like this, but that is not happening. What we are seeing is that the phone is using the language that appears highest on the Language list in the International section of Settings.app. For my phone, the highest non-English language on the list is French, so when I run the app, it is localized for French. If I change my phone to German and then back to English (which changes the order in the Languages list), the app then localizes to German.

How can I ensure the app defaults to German for non-supported languages? I used this tutorial to set up the locales for the project. This includes removing the default "English" locale that is created when you first localize a file. In the project file, I've added:

developmentRegion = de;

Also, in the Info.plist, I have

<key>CFBundleDevelopmentRegion</key>
<string>de</string>

With no success.

Any ideas would be appreciated!

Defaulting to a particular language is not what you should strive for. Suppose a japanese user living in France and fluently speaking French has his phone set to Japanese. Your App would default to German, despite it having a French translation; I guess that's not what you want and it's certainly not what the user wants.

For this reason I suggest to respect the language prioritization as set by the user.

Since you don't want to support English but have developed the App in English, the easiest thing you can do is to just get rid of en.lproj right after compiling. This will leave the app with only the languages you plan to support, and the iPhone will chose the language best suited for the user, as set in iPhone's defaults.

There is a pretty straightforward solution to deleting a specific localization:

Let Xcode build the App with all the present localizations and just before code-signing kicks in delete the en.lproj folder and all localized files for that language are gone. You can easily do this by adding a Run Script build phase to the target, containing this one line of code (it's a Bash Script):

rm -r "${TARGET_BUILD_DIR}/${PRODUCT_NAME}.app/en.lproj"

Code Signing always kicks in after all build phases have completed, so just put that build phase at the end of your current phases.

Note that this increases the time to build because Xcode recreates all English files, so you might want to disable this step during testing.

I hope that's a viable solution for you.

Concerning "the app must fall back to German in the case that an appropriate localization doesn't exist":

Question is what is an appropriate localization? If the user's third choice is French (after 2 unsupported languages), this solution will make the app fall back to French, which is an appropriate localization. More appropriate than setting the user's fifth choice, German, by hand.

What happens when an app launches is simple: The OS descends the users language list, as set in Preferences, until it finds a matching localization, and uses this language. The reason many apps default to English and not German is simply because English appears on most user language lists above German. There is no inherent language preference to the system. If you delete the English translation, only the languages you want to support are there, and of these languages the one higher on a user's list is taken.

I don't like posting this answer since it runs against Apples Human Interface Guidelines. Localizations are something the user should set, not something management should decide, so managers requiring a certain default language don't understand nothing and should change business.

That being said, there is a way to force iOS using certain languages in a certain order. I mainly use this to debug localizations without the need to set the device language to something else, whether it is possible to use this to solve the nonexistent problem in this question I can't tell.

There is a key AppleLanguages in the user defaults that dictates the order of languages to be used, normally set to the order the user sets in iOS's preferences. If you change this order, the app will try to find localizations in that order first. What you could do is read the current language preferences and decide to default to German as follows:

NSArray *langOrder = [NSArray arrayWithObjects:@"de", nil];
[[NSUserDefaults standardUserDefaults] setObject:langOrder forKey:@"AppleLanguages"];

Note that you need to do this in main.m before UIApplicationMain, otherwise you need to restart the app for this change to take effect.

I cannot state enough that nobody should do this in a real app, unless you go all the way and implement a preference setting that allows the user to change the language manually. If you just default to a given language, the user has no option to change your choice.