Notify existing customers of new apps

I am building a range of related products. People who have bought one will likely be interested in the others.

What is the best way to notify my existing customer base of new products as they appear?

The most horrible way would be to flush an update of each existing app which notifies the user that there is something new.

Obviously this will annoy the hell out of users if they already have seven apps installed, all of these updates that don't do anything but give them the same message.

So maybe I can just maintain a web page somewhere (say for example some page on my wiki, so I don't even need to worry about web hosting and getting a server) and each new bulletin gets a number. I could just write it in plain text:

:

13. {sep 05 '11} { AppX launched }

14. (oct 22 '11) { AppY launched }

and then each app would contain a module that checks whether there are any new notifications.

the first app that gets run that开发者_JAVA技巧 detects a new update

(1) notifies the user

(2) makes a memorandum in some shared space that this notification # has already been delivered

this will prevent the same notification from popping up on each application when it is run.

but this requires some common space visible to all of my apps. can I do this?

EDIT: I have been told I can use ' shared keychains ' to do this. How can I implement this?

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Simply email your customers when new releases of your apps appear. You only need to ask the users for their email address in each of your apps and create a user account on the server. So you can make sure that a user will only be notified once.

You could send a push notification to each device when there is new content. When the device registeres for push notifications on the server send the UDID in addition to the push-devicetoken. With the UDID you can then make sure that each device only receives one push alert even if there are more than one of your apps installed. You would only send one push notification for each UDID.