If this is working so well, why is there still no version of Yahoo Messenger—a core product—for either Mac OS X or iOS?
And apparently there's a native OS X client coming, as well: http://mashable.com/2015/12/03/yahoo-messenger-is-back/
It's still mystifying that there was no iOS or Mac version for such a long (albeit temporary) period of time.
Also mystifying that I apparently deserved a -4 for this comment. Seems valid to me to note Yahoo not having an app on iOS or Mac OS for well over a year.