Question regarding iphone allowance of custom notifications

I have an app that I am working on, and开发者_Python百科 part of its main functionality is to alert the user to do something. So even though they aren't in the app, I want to be able to pop up an alert from the app, reminding them to do something. Is that allowed with the iPhone sdk? Maybe it isn't even a big deal at all, but for some reason I was thinking that it would require background processes or something that may or may not be possible. Anyone who has any thoughts about how this would be implemented would be greatly appreciated. Thanks!

Check out the Apple documentation on push notifications. Short of jailbreaking and distributing your app outside the App Store, there is no way to run background processes at this time.

It is allowed through notifications, though you will need a server to actually send the notifications to the user. There is no limit to the number you can send, although the user may very well decide to shut off notifications or delete your app altogether if you are too spastic with them. Make very sure the user understands the notification volume they will receive and agrees to it...

The way the system works is the user gets a notification message (and/or sound) and can decide to open your app or not, as the time of notification.