Microsoft Excel can easily do this.

My portfolio dropped to $350,000 when our great government broke up Microsoft.

That being said, I don't see the Costco's, Amazons, Microsofts of Seattle leaving there anytime soon, and so I do think there will always been high demand for property in Seattle, but the double digit annualized appreciation that has been occurring over the last decade, I don't see continuing.  

The high-end "executive" rental is in high demand here right now with tons of people moving here who are looking to buy property who need to rent until they find something, people who sold their homes and aren't able to find a replacement property, nomadic tech-workers working remotely/on contract assignments with google, microsoft, etc. 

This has also happened in Seattle and surrounding as people are pushed to the outer fringes while Google, Microsoft, and Amazon have taken over and dominated the housing and rental markets.

Don't see how this is different than purchasing Microsoft Office or another program to help run number more efficiently. 

I have a tab for each property.I keep a word doc for vendors with a table of contents with links to headings such a plumber, hvac etc.I get recommendations from my large local RE club whether I askednor someone else asked I keep this contact info for future reference.I have no need to pay for a service when I can easily and quickly manage with systems I have built using Microsoft office that I already have.Tenants pay rent via deposit, ACH Zelle or PayPal.

Microsoft though. 

Included with that subscription is Microsoft Forms. 

I would liken buying a unit here to investing in Microsoft or Apple stock.Prospect Park South- To me, this is the most undervalued of the areas you mentioned and has the greatest future upside potential.