For iPhone 5 +
Its a app for events with eventexpresso wordpress plugin and maybe your native JSON API add-on. The app will show (like a dashboard) a page (template) according to the type of user. So, HTML5 should be the best option for this app.
It will NOT be in the AppleStore, but must have performance installation and processing, to make this page display
I will do the customization of CSS, I need the base.