for example, if i update the content of my website how can i make my ios application verify if there is new content and only to make an update IF there is new content available.
I hope i was clear on the question, i apologise for the bad english.
Best Regards
use a timestamp in the html meta tags of your web page.
If app has seen the timestamp before then no update is pending. If new timestamp then do update.
Edit 2: I see you are using wordpress. For example the
all in one SEOplugin will let you add keywords to your posts. Use them on the server side. The app can scan your site for the keyword/timestamp