Middleman is an interesting new Swift library to easy using x-callback-url in your app.

CallbackURLKit looks like a nifty Swift library for implementing x-callback-url.

Sebastian Rehnby has published SBRXCallbackURLKit on Github. SBRXCallbackURLKit is a “simple library that makes it easy to add x-callback-url support to your app.”

SBRXCallbackURLKit has a block-based API for declaring URL handlers and Cocoapods support for easy integration. Worth a look if you are getting started on URL scheme integration in an app. You might also want to look at Inter-app Communication, which works in a similar fashion, and see which best suits your needs.

Nice overview of activity in URL schemes development on iOS – with pointers to some great projects to make it easier to implement URLs in your own apps.

AppCubby’s excellent app Launch Center Pro has updated to version 1.1, now with excellent x-callback-url support. Still waiting on official docs on all the possibilities, but Federico Viticci will get you started on some of them at MacStories.

Great article about some of the things you can accomplish with x-callback-url support.

Excellent introduction to some of the powerful things you can do with Pythonista and URL schemes to automate workflow on iOS.

Notesy, a popular Dropbox-integration text editor, has added a great set of x-callback-url compatible URL actions.