Even with 200 STRs it isn't a broad enough cross section to assume the changes.You would need to have millions of data points to show the trend IMHO. 

Quote from @Chris Lo: Which platforms/websites do landlords use to find the rent rate, how long the rental properties have been on the market, and all the details about other rental properties?

What if something changes with how that platform works?

Navigating the Surge in Rental Application Fraud: A Guide for Landlords and Property ManagersIn recent years, the rental market has experienced a troubling rise in application fraud.

Pick a screening platform/application that makes sense for you.As for meeting the applicants, I recommend meeting them at the property to show the place to them rather than getting coffee or food with them.

So accepting and approving multiple applicants is the norm?

Here's a detailed guide on how to screen applicants: Application Screening Guide 

I am seeking recommendations for an app that can integrate with multiple platforms.

The only example I can think of is that I asked an applicant questions about their credit report.

Are you not necessarily denying him based on screening criteria - Some landlords make it a requirement to view the property prior to letting the applicant apply.