Great way to keep your landlord accountable, it has a history to log each time the sensor activates, handy for tracking unauthorized entry to your unit. It can also be setup with Alexa to yell when someone opens the door. I have it set loud enough to wake me up from sleep wearing earplugs, and it is reliable, so good peace of mind. I would recommend having the hub set on a UPS with your router so it continues to work in the case of a power failure.
Ideally your landlord won’t be as shady as mine, but if they are, this is a good way to remind them that they can’t do whatever they want.