Every client who has an own mobile application has usually his own domain name too. Your domain name will be inserted in your mobile application contact area. Pls. insert your domain name here as step 1. If you don't have an own domain name right now, but you wish
to register the domain with Nodowntime Domains, you can get all thatís required the simplest and fastest way on the one place here
If you don't have a domain name and wish not to have one, then just put the words withoutdomain.com but this is not the usual way (your mobile app users usually expect to recognise your domain name and your 'brand').