How many coins do have windows phone wallet? Would again be a step in front of the rest.
Hmmm... I'm not sure to understand properly your question. If you mean how many windows phone wallet app are available, I want to say that I don't know exactely but only a few : Dogemuch for Dogecoin and Spectrocoin are the only 2 results I have found (I mean for a real windows phone wallet and not only a balance viewer).
In order to have the maximum Digibyte adoption, it would be great to have (not immediately, but one day^^) wallets available on the 3 major Smartphone OS : iOS/Android/Windows Phone in order to cover 99% of the users. But Digibyte team probably know it...