Intelligent home IoT devices I use (and love).
Ring video doorbells
Basic concept: When someone presses the doorbell button, you get a video link to answer on your smartphone (iOS/Android), even if you are not home.
Extras: motion detection – you can find out who is at the door even if they don't push the doorbell button. Doorbells can be charged with solar panels (sold separately) or batteries (spares sold independently). Don't forget to buy a Doorbell chime (sold separately) to hear the doorbell ringing even without a phone.
Basic concept: Indoor and outdoor cameras (with floodlights) that report movement to your phone (and Doorbell chimes) if someone enters your house or yard. You get a live video link for each event.
Extras: Alarm sound, loudspeaker. Some models support solar panels, while others are wired.
Garage door opener
Basic concept: open garage doors with your phone/watch (even if you are away from home)
Note: the particular one I use is no longer available. However, there are several replacement options.
HUE Phillips lights/switches/sensors/etc
Basic concept: Led lights you can control remotely, dim, use to set a particular mood, etc.
Extras: too many to even mention.
Note: These things are expensive and addictive, which is a terrible combination.