It's not supported by Hubitat, but in my opinion the best option for an iOS user is Homebridge.
There's a community plug-in and app for Hubitat. With this and an Apple TV 4 or later, you can control you hub remotely. Anything you can control locally can be controlled with the iOS Home app. You can even monitor sensors. You just need to build a Homebridge server using either a Raspberry Pi 3 or a spare computer. Not too difficult. Loads of instructions out there and many of us have done it, so there's lots of help here too.
That would also cover notifications too.
