While Pushover is quite popular, natively supported, and more versatile (supports "levels" that can, for example, override "do not disturb" on iOS devices for specific notifications, among other things), my needs are more simple, and I also have an existing Samsung account for SmartThings (the platform I previously used). In my case, the Hubitat driver and ST SmartApp from here is working well for me: Route Hubitat Notifications to SmartThings (App and Driver)
Plus, it's free! 
(If you already have an ST login. You don't technically even need the hub for this since it's all cloud-based.) That being said, if I ever want to use notifications more, I'll probably spring for Pushover...
