Ruby text/ Furigana in ios

I am currently trying to display some text in Japanese on a UITextView. Is it possible to display the furigana above the kanji (like below) in a manner similar to the < rt> tag in html, without using a web view?

A lot of text processing is involved, therefore I cannot simply use a web view. In iOS8, CTRubyAnnotationRef was added but there is no documentation (I would welcome any example), and I am also concerned with the lack of compatibility with iOS7. I thought that it would be possible to display the furigana above with the use of an NSAttributedString, but couldn't as of yet.

In the end I created a function that gets the kanji's position and create labels every time, above the kanji. It's quite dirty but it's the only way to insure a compatibility with iOS7.

However I have to mention the remarkable examples that you can find on GitHub for the CTRubyAnnotationRef nowadays like : http://dev.classmethod.jp/references/ios8-ctrubyannotationref/ and https://github.com/shinjukunian/SimpleFurigana

Good luck to all of you !