Hotel Management Software for Holidays Home -- 2

I have got an apartment block of 6 apartments been let as a holiday home in a remote area but with internet access. I am after a software like hotel management software that will be able to do the basics of a hotel management software but also monitor each apartment occupancy and rate of occupancy. This can be achieved by using occupancy sensors or any other sensors on the market that can detect that the apartment is occupied and used some logic to determine if the occupation is temporary i.e cleaner (please note that the cleaner should be able to tell the system the apartment is been cleaned). My preference will be for an off the shelf product but consideration can be given for a purpose system provided that all the hardware is off the shelf.

The main purpose of this system is to track cash flow against occupancy

Regards