Your android server will be acceced remotly as a web server , ftp server or other server. The dyndns allow you a get a similar fixed ip. With the dyndns pro, you can host a web site in your mobile or your tablet. ex. your blog, your home page, your company android server..
This application could be used by companies that uses employees smarphones to get and fetch some working data (logistic, gps,etc).
See web site http://android.dyndnspro.com