Skype for Business App for Mobile Devices

The Skype for Business Application is communication software that you can use for instant messaging, voice & video calls, real-time collaboration, and more.

For download, installation and setup go here: 

Skype for Business, Mobile Devices

To setup Call Forwarding or Simultaneous Ring after the App is installed go:

Skype for Business, How to forward calls, redirect calls, and use simultaneous ring