My solution (perhaps permanent) has been:
I set up a boolean hub variable "SimplisafeArmed"
I set up Tasker on my android phone to monitor notifications from the SimpliSafe App. (Works even if phone is in "do not disturb" mode.)
When Tasker catches a simplisafe app notification containing "System Armed" it calls a cloud endpoint. If it gets a "System Disarmed" notification it calls a second cloud endpoint.
The cloud endpoints trigger setting the hub variable accordingly.
I have some Hubitat apps that monitor the variable for changes to do stuff like send pushover reminders to set the alarm if not set, change the color of a lightstrip so that everyone knows the armed/disarmed status etc...
You could really avoid using the hub variable, but I tend to like to add that layer for future simplicity when adding related but not directly connected functionality.
Could also easily monitor for other messages for simplisafe errors, triggers, updates, etc and do similar messaging / color light changes for those things. (Blinking red Hue lights if alarm was triggered?)
Pros:
Super easy setup, and simple apps (Tasker is a bit of a learning curve, but this is one of the most simple sets of tasks.)
Easy to change if SimpliSafe changes their message structure.
Pretty dang fast response time.
Cons:
Phone has to be on all the time. (Do people turn theirs off??)
May not work properly if you use the phone app to turn on/off the alarm - may not get app notifications when IN the app - I hardly ever use the app to arm/disarm -- will investigate further. EDITED to add: Does NOT work when USING the SimpliSafe App to arm/disarm, as there is no notification message created when directly using the SimpliSafe app. I've since added an "Armed" and "Disarmed" Tasker app Icon so that I can manually flip the Hub Variable if necessary. Not a huge deal to me, as I probably only use the app to arm things once a month or so...
Pro/Con?: Can't arm/disarm the alarm using this method. I personally prefer this. (Now that I think about it, though, I wonder if you can use Tasker to manipulate the SimpliSafe app...)
Have to have SimpliSafe App on your phone. (Not really a Con for me...)
Unknown:
iOS - no idea what works like Tasker on iOS. Maybe something?
Been using the scheme for about a week now, and it seems mostly flawless. Only operational error occurred when I accidentally deleted the relevant scenes in Hubitat (Changed from Sengled to Hue lightstrips, and deleted the wrong scenes -- need better naming convention QC.)
