The batteries end up costing more than the device though  

A "smart" thermostat that can connect to devices yet still easy to use for any non-techie buyers.  

I wonder what else landlords could do beyond this device to create a win/win.

 @Mark Smith  You could use a pay-as-you-go internet device such as internet-go.com.

Check it out of other devices and friends computers.

Smart home device like Google smart lock.

Develop a neighborhood watch of sort and negotiate with several security alert companies like First Choice or ADT to get a discount on their device.

They have the lead free nuclear testing device.  

All contracts, options, or other devices not based upon a substantial consideration, or that are otherwise employed to permit an unlicensed person to sell, lease, or let real estate, the beneficial title to which has not, in good faith, passed to such party for a substantial consideration, are hereby declared void and ineffective in all cases, suits, or proceedings had or taken under this chapter; however, this section shall not apply to irrevocable gifts, to unconditional contracts to purchase, or to options based upon a substantial consideration actually paid and not subject to any agreements to return or right of return reserved.Then you have 475.42 which states brokering without a license is a 3rd degree felony:475.42 Violations and penalties.—(1) VIOLATIONS.— (a) A person may not operate as a broker or sales associate without being the holder of a valid and current active license therefor.

I’m looking for a noise monitoring device for my STR.