Godzippa library is no longer being maintained as of iOS13+ and macOS 10.15+, as the Foundation provides equivalent functionality through APIs like compressed(using:) and decompressed(using:). Godzippa regardless is still available to developers and can easily be implemented via its repo.
Keychain Access is program that rememebers password and account information so the user does not have to remember and manage their passwords. Although Keychain Access is only on macOS, it also collaborates with iCloud Keychain so you can share account information across all your Apple devices.
Starscream is a conforming WebSocket (RFC 6455) client library in Swift. Starscream has numerous features such as; it conforms to all of the base Autobahn test suite, Nonblocking (Everything happens in the background, thanks to GCD), and supports TLS/WSS among others.
The Yahoo iOSSDK is open source to developers in source and binary forms with the freedome to apply modification so far as several terms and conditions are met. The Yahoo pluggin is fully applicable to Xcode and it is required you sign up for a new application ID to get your OAuth consumer key before application.
Aspects is a delightful, simple library for aspect oriented programming by @steipete. Aspects allows you to add code to existing methods per class or per instance, whilst thinking of the insertion point e.g. before/instead/after. Aspects automatically deals with calling super and is easier to use than regular method swizzling.
ProcedureKit previously known as Operations is Swift framework inspired by WWDC 2015 Advanced NSOperations session. ProcedureKit supports all current Apple platforms with the minimum requirement being iOS9.0+, macOS 10.11+, watchOS 3.0+, tvOS 9.2.
TBXML is a light-weight XML document parser written in Objective-C and designed for use on Apple iPad, iPhone & iPod Touch and Mac OS devices. TBXML aims to provide the fastest possible XML parsing whilst utilising the fewest resources with this being achieved at the expense of XML validation and modification.
KolodaView is a class made to simplify the implementation of card-swiping (like Tinder) on iOS. It adds functionality such as a UITableView-style dataSource/delegate interface for loading views dynamically, and powerful view loading, unloading.
Mantle makes it easy to write a simple model layer for your Cocoa or Cocoa Touch application. Mantle can still be a convenient translation layer between the API and your managed model objects if you looking to use core data in your application.