@Michelle Fenn  We had properties listed for sale, posted on local MLS, propagated to Realtor and maybe 100 other websites including zillow, trulia etc. 

We're wondering about various what-if's though, such as what if the people tear up the place, what if we don't want to rent to someone in particular due to references or credit or pets, etc.

There are a plethora of websites where homes can be listed - not just the ones dedicated to home sales, too.4.

@Sushil IyerWith my experience, to analyze properties effectively, you can start with resources like MLS listings, Crexi/Loopnet, tax assessor websites, or paid tools like Costar and Reonomy.

I am definitely referring to a house that was already insured as a rental, not as a primary residence.

@Liam Alvarez  I've never seen an app or a website that analyzes all markets and spits out the top 3 you should invest in for the highest returns. 

Can you put one on Houfy or similar site.You can always have one on YouTube and reference the link.

I know nothing about the above firm you mention, but a quick look on their website shows they are likely offering you DSCR, so just general things to look out for in that world. 

Does anyone have some really good websites for accurate up to date data for vacancy rates, median rents, average household income, etc? 

In reference to the recent bubble burst as an anomaly and not the rule, you can still safely assume that real estate prices will continue to climb over time even though more modestly than in the past.