Actually UIWebView way is so painful, mobile safari does not support WYSIWYG rich text editor area.
From Zoho FAQ :
I can't create or edit documents on my iPhone, the keyboard doesn't show up when opening iZoho on iPhone. What's the problem?
It is an issue with the iPhone as the safari browser doesn't seem to recognize the rich text editor area and hence the keyboard isn't appearing. This is not an iZoho specific problem as all the applications that use a WYSIWYG editor face the same issue. We hope that Apple will address this issue soon and come up with the next version of iPhone's Safari that supports rich text editing. As a workaround, we may give a plain text editor for users to edit/create their documents if this isn't corrected in Safari's next version.
You should implement rich text editing by yourself :(