I think these 2wo can be merged
What do you think?
Strictly speaking, you can develop a Salesforce mobile client app on iOS without using the Mobile SDK, so they aren't strictly synonyms. That's not to say that all questions are correctly tagged, though...
I second what Patt mentioned. You could always get questions related to
A) Using Mobile SDK for iOS B) Using Salesforce1 on iOS which has no relation to Mobile SDK C) Running Mobile VF pages on iOS (iPhone, iPad), which again may/ may not have relation to Mobile SDK E) Admin related questions on iOS which again may not have any relation to Mobile SDK