Urban Push is a WordPress plugin that utilizes the Urban Airship API to send a push directly from the WordPress “new post” page. You MUST have an account with Urban Airship to use this plugin. You can send a single push to up to 4 Urban Airship applications. After a push attempt, you will see one new custom field entry for each configured Urban Airship application. It will say push sent for followed by the name you chose for your Urban Airship application. The value of the custom field will contain the response returned from Urban Airship. For a successful push, the response is usually “(null).”

More features are coming like:

The ability to set your aps options (badge, sound, etc..)
The ability to choose which app to send a push to (or all).