We also have a lock box at each house just in case the batteries die in the keypads.

It’s usually in the spring and fall to do maintenance (batteries, turn off the outside water, replace filters, etc. but it gives an opportunity to catch any issues - both maintenance that they may not notice like failing caulk in the tubs, and also anything damaging they may be doing.

We need to replace, fix some doors, some painting, little tile job, replace sump pump battery back ups and outdoor stuff as well, etc. 

Make sure you get a security deposit and set expectations from the beginning (ie: landlords don't replace light bulbs, batteries, etc). 

All the sensors and the keypad run of batteries and the base unit plugs in but has a battery backup.You would have four entry sensors for the four doors, at least one glassbreak sensor, and at least one motion sensor.

Examples: replacing burned out light bulbs, furnace filters, batteries in doorbells, etc.

Regardless, a lot of basement/foundation contractors can install a battery-operated sump pump for exact scenario of 'if the power goes out'.

Basic issues could be as simple as them calling you on a Saturday night because the remote controls battery went out or the internet suddenly stopped working because of the rain.

We change the batteries once a year and in case the batterris die or lock malfuntions, we have a key in a lock box attached to the house somewhere, like the  water spicket or gas meter.

Another vote for YourPorter.I even created an offplatform website through their interface, though I am trying to figure out how to best integrate electronic lease agreement signature.The only thing I am trying to figure out is their Cleaning module - how best to send automated communications to my cleaner.