Note: app requires iOS 8.1 or higher
It can be downloaded from the Apple iTunes store
After installing and then loading the app. Enter your sign-in address (for example, firstname.lastname@example.org) and your normal password, and then tap Sign In.
Enter your mobile number with country and region codes. This number is only used if a Voice Over Internet Protocol (VOIP) call is used.
Tap Next to start using Skype for Business.
To sign out of Skype for Business
Tap your picture, and then Sign out.