The Skype for Business team at Microsoft hinted strongly that a version of the just released business messaging app is coming to the Windows Phone platform at some point. The team made those statements as part of their Reddit AMA session earlier today.
At the moment, mobile devices can still use the Lync 2013 app for Windows Phone to connect to users who have the Skype for Business desktop client. During the AMA, the team stated that mobile versions of Skype for Business would be released for iOS and Android "in the coming months". When a Reddit reader asked about Windows Phone as well, the answer was cryptic, but still hinted the app was indeed in the works.
"I'm running a Lumia 1520. I cannot confirm nor deny the existence of a Skype for Business mobile client on my phone. Hopefully you won't run into me at Ignite and accidentally see me using something like this on my phone...."
Another member of the team also tried to reassure the Reddit audience they have not forgotten about Windows Phone and offered this hopeful prediction:
"Don't be bummed out. I own three windows phones at the moment, and I can tell you, Better things are coming."
It's likely that any Skype for Business client for Windows Phone that's released by Microsoft will be made for Windows 10 in mind as a universal app.