Live broadcasting to YouTube is one of the many features that the official YouTube app is now capable of, but this wasn't always the case, and this is where apps and services such as Sony's 'Live On YouTube' application came in handy, as it allowed users of the app to live stream their content straight to YouTube. It was a nifty feature for all intents and purposes, but its only caveat is that it was limited to Sony devices. As of today, 'Live On YouTube' is no longer live. Sony mentioned yesterday that the app would be pulled offline and that they would be shutting it down, and they made good on their promise.
While this seems like an unfortunate event, and it may be, slightly, what's important to remember is that there is such a thing as YouTube Live now, where you can live broadcast with the official YouTube app, so there is really very little reason for Sony to keep their own app going for such a purpose. In addition to YouTube having live streaming baked in, Live On YouTube will reportedly not support Android Nougat and above, so even if YouTube didn't support live streaming from the app just yet, Sony devices would eventually not support the app anyway.
Sony's short message was just that, a very short message, and gave no reasons as to why they were shutting the app down, but the reasons explained above would pretty much sum up Sony's decision. If you use a Sony Xperia device and have opened the Live On YouTube app recently, then you may have already been greeted with the message. Of course, it's also possible that Sony will be sending out a small update which proactively removes the app from the phone as there is no point in leaving it there if it won't operate. Having said that, there is no indication of an update to uninstall the app, but it would make sense for Sony to initiate something like that. Users can also choose to disable or uninstall the app on their own as well, and if live streaming was a feature that you actively engaged in, then YouTube will now be your new home for those kinds of tasks.