Build an iPhone App

Hi I require a simple iPhone app which allows the following: --- Background --- The client is a sporting organisation. They often need to notify parents and players of last minute changes to games. They don't want to have to maintain a large database of ~1800 phone numbers and want a simple way they can send notifications out to their users. --- How it would work --- - The user installs the app and subscribes to one or more of 5 available "feeds". - The administrator adds a new "news item" to one of the feeds which is just text information - The item is pushed out to all users who have subscribed to receive notification about that particular feed. This should be in the way of a push notification which can be read in further detail by opening in the app. - The item can then be deleted manually or is automatically deleted after a week. --- Example of usage --- Player 1 is on a Womens football team. She has installed the app and subscribed to the "Womens Football" feed. On the day of her game, it starts raining and the game is called off by the sport officials. The administrators log into the system and add a new "news item" to the Womens Football feed. It reads "Womens A grade football game @ 3.30pm is cancelled" Player 1 gets this come through to her iPhone as a push notification and is now aware the game has been called off. --- Considerations --- - I'd like to expand this to an Android app in the future too, so the method of administration (i.e. adding new "news items") should be created keeping this in mind. Ideally, I'd have the administrator log into a web page, add the news item, click submit and it would then go out as a notification to all the users regardless of whether they are iPhone or Android. I'm open to suggestions about how else this administration could be accomplished though.