The Unwind Segue

http://makeapppie.com/tag/uipickerview-in-swift/ (note links therein to other related posts)

UIPickerView class reference

https://www.testflightapp.com/ (original site, pre-apple buyout, it seems like you can still use it though. using this there is no need for any review or approval by apple, but it does require you to add the testers’ devices to your apple developer account, which deducts from the 100 devices/year limit)

Test Flight Beta Testing – From Apple

Automating the process of making your app icons in all the various sizes

Naming layers in Photoshop to automatically generate the iOS assets (using Photoshop Generator)

see the links at the bottom of this post: http://blog.anaara.com/2014/12/03/core-data-cloud-services-for-ios-in-swift/