You said you collect rent using an electronic format so I’m assuming software such as AppFolio or Buildium etc which can allow tenants to complete rental applications online and pay rent online.In your lease do you specify that all tenants must pay in an electronic format whether it’s perhaps signing up to a service like AppFolio and using that.

Top Investor app doesn't have watch lists but you can monitor particular neighborhoods (it uses census tract as a proxy for neighborhood)

If you're determined to do bookkeeping yourself, look at simpler software such as Stessa which is free.

I'm looking into property management solutions. I have 1 SFR and closing on a 4plex. The properties are in IL and I live in CA so looking for something that would make sense for a portfolio that is just starting out b...

I use a software and do massive code calling and it's lead me to a dead end.

Software Development background here too!

Forcing them to pay online using your software or paypal could be a better option as well. 

That’s the way the accounting software works.

Very cost effective and the software is free from them.

Along with the uncertainty of the Covid 2nd wave, it will be interesting to monitor closely.