The best tutorial to learn how to code an iOS Application Extension is http://www.appcoda.com/ios-8-action-extensions-tutorial/
I have experience programming in different languages but I am new to Swift and Apple OS in general. I wanted to learn how to code an Action that would be linked to the “Share” button in Safari. My goal was to grab (scrape) information from a website and send it to a separate app.
The best tutorial I found is this.
http://www.appcoda.com/ios-8-action-extensions-tutorial/
At the bottom of the page there is a link to the complete project. The “Capitalize” section of the project really helped me with accessing content on the page loaded in Safari.
I used this with Xcode 6.3.2 and I only had a few small problems with variable types.