We already publish the IOS application, Now we want to publish its message extension. Is this possible ? .If yes then How? Additional question is that how to upload separate iMessage extensions. what are the steps? Any help would be appreciated. Thanks in advance.
Is this possible ?
Sure
How?
Add new extension to your exist project and share it to iTunes. In the new build it will be appear.
what are the steps?
There are a lot of tutorials about creation of iMessage extension. Try to use them. In several words: link
Check this link too - iMessage integration to your app
upload iMessage app seperatly
iMessage applications can be developed and distributed in two ways:
As an extension to an existing application:
As an extension which is an independent application