I'm trying to figure out if it is a requirement for apps submitted to the iOS appstore to show the progression of data being down/loaded (by means of a progress bar or something similar) or if simply letting the user know that loading is in progress is sufficient. My app generally only loads for 2 seconds so i figure showing a progress bar is not really necessary but if it is a requirement then obviously i have no choice. Here's hoping someone can enlighten me :)
For a two second load (and you can ensure that that's pretty much what it will ever be on all devices supported) I think you should be perfectly fine. Think of Apple reviewers as the most impatient user you have ever encountered. If you normal user is watching you app load and thinking "Is it frozen or still loading something?" the Apple reviewer is going to say it's frozen and close your app and start the write-up saying it froze.
For short activities I see no need for a progress view (I do them anyway, but that's just my preference). For long activities make sure to show some progress indication other than the beachball of death activity indicator.