Hi TD... You'll need to enrol into the Apple VPP programme. Download the VPP token from the site, upload this to Airwatch environment. It will then send an email to all enrolled iOS7 device users inviting them to join the VPP programme. This will allow the console administrator to push applications to the device that has that users Apple ID logged on to it. For silent app installs, the iOS devices need to be supervised. From the VPP site, search for the applications you want, select the required quantity, purchase the app(s). The token then sync's with the Airwatch console, so your VPP apps appear under the purchased apps section. From there, the admin can distribute those apps to the devices enrolled to the MDM environment.
Please note, I work for Airwatch.