My #1 recommendation is Big Nerd Ranch books. Depending how much time you're willing to spend... I'd recommend their Objective-C, iOS, and Swift books in that order. It might just be my learning style, but the foundations they cover in the Objective-C were super helpful once I took the time to go back and read it (after trying to jump straight into Swift).
Other good resources Ray Wenderlich's books, Mengto's Design+Code book, and iOS path on teamtreehouse.com.
My #1 recommendation is Big Nerd Ranch books. Depending how much time you're willing to spend... I'd recommend their Objective-C, iOS, and Swift books in that order. It might just be my learning style, but the foundations they cover in the Objective-C were super helpful once I took the time to go back and read it (after trying to jump straight into Swift).
Other good resources Ray Wenderlich's books, Mengto's Design+Code book, and iOS path on teamtreehouse.com.