If you are developing an app it is advisable to contact the group as soon as possible. Depending on which category your app fits into the group will either need to register your app or approve it going forwards.
In general if you are creating an app that will need to branded as University of Birmingham the group will need to sign off on it's development and you will need to fill out a Mobile App Approval Form (PDF). This is to maintain a consistency of approach and to ensure that work is not duplicated.
The group will stay in contact with you throughout this process and will get back to you with an answer as soon as possible.