I would suggest a way to set multiple sensors to trigger the same actions (any sensor opens/detects motion, then turn on a smart plug (with a siren plugged in).
Also, the ability to create a shortcut to quickly enable/disable trigger rules all at the same time from the home screen.
Finally, when you set a trigger rule and enable a schedule, as of now, if you make the trigger all day then go back to the schedule it does not remember the original time setting. It makes you re-enter the start and end time every time you re-enable the schedule. It should remember the previously set schedule.