Slow! Needs more features.
First problem: I rely on the "Conversation History" folder in Outlook to find *all* of my SfB chats, not just the ones I happened to have on my Windows VM. It stinks that this app cant sync those and add them to my mailbox folder somehow. Microsoft controls O365, Exchange Server, Exchange Online, Skype for Business Server, Skype for Business Online, the Outlook client in Windows, and this SfB mobile app; no reason they cant make it work. Worse, they provide no way to simply email the conversation to myself so that I can put it in my "Conversation History" folder manually.
Randall King about
Skype for Business, v6.12.0