I have UITable to display different animals. When you select a cell in the table, a new view controller with a large UIImage is pushed. Currently, when you zoom in on the image, a UIAlertView is triggered that asks the user if they would like to download hi res images. If they click yes, the "hi-res-flag" is set to "yes" in user defaults and they no longer see the pop up. However, if they select no, the hi-res-flag will continue to pop up each time they zoom in on a photo.
Instead, if they answer no, I would like to have this flag pop up occasionally. Not every time the click a cell in the species table, nor every time they open the app. Something more like once or twice a month. Is there a way to use time in the logic of an iOS app? For instance, erase the value set for "high-res-flag" (if already equals 'no') in user defaults, once a month?
Store the time you showed the alert last in the user preferences, and then check that value every time before you present the alert whether a certain time has passed.