How should I manage others property? Any software recommendations?

[Frazz Wick]

I have someone who would like me to manage their single family home rental. I currently manage my own rental now, and considering this to be the "kick in my pants" to get my property management license and start a small business doing property management professionally. I've been looking around for different types of software to use and have had difficulty finding anything that works as a middle man between the landlord and tenant. In the past, I've used Zillow Rental management, but it looks like I have to be landlord to use that program. Does anyone know of a software built for property managers? Or would my contract with property owner give me 'landlord' rights?