Suggestions

Here is what I think could improve Simplisafe. It's a lot the general theme is to catch up with other companies that have all this stuff but to allow people to really use one app and to expand the systems abilities to both protect people but also make small things that can be automated easier and to give people more customization for what their system will or won't do.
Outside camera WITH solar panel because wiring isn't always practical and changing batteries is annoying
Optional service for continuous recording on cameras
Battery powered door bell with a separate model having a solar panel built into the casing
Adjustable false alarm times meaning if my alarm triggers I want to be called some point between immediately or a minute
Interior battery backup for cameras
Two in one smoke and co detector
Make a explosive gas detector
Use of auxiliary sirens during a environmental alarm for smoke, co, water, temperature
Emergency dispatch for temperature sensors above a safe temperature which could indicate a fire that has not reached a detector
Door timers so you don't leave a door open too long
Automatic arming so you don't forget about arming the system in home mode at night
Bring back human calling for test notifications
Better integration to control your smart home devices from the app or Simplisafe versions of those devices for example thermostats, lights, plugs