Maybe instead of iphone specific app Zoho should standardize on an HTML5 web app for mobile like google.
My frustration with mobile apps is usually they only come only come out for one carrier. Just supporting the Iphone would be a mistake!. Lots fo thech's also use other smartphones. I have both Android and Palm WebOS phones. It might be better to support an HTML5 web based app for mobile rather than an app built for a specific phone. That way you can say you support all of the modern smartphones....