Kotaku reports that Apple has approved the app, and then taken the approval away, citing “business conflicts”. Things stayed that way for nearly a whole year until now, and Apple has finally granted approval for the app once again.
The app also supports controllers via Bluetooth. This includes the Steam Controller and Made for iPhone (MFI) controllers.
On the app’s page, we see a familiar list of requirements for the app to work. This includes the need for the iOS device to be on the same local network as the computer running Steam. That said, Kotaku also reports that the Android version of the app has since been upgraded, so that both devices no longer need to be on the same network.
It remains to be seen if the iOS version of Steam Link will be given the freedom that was recently granted to the Android version. At any rate, this means you have more options when it comes to playing games on Steam.