I do not have a huge portfolio, but for the properties I management myself I've been using: Cozy.coThey make marketing the property, accepting applications, screening tenants and collecting payments all pretty easy. 

Go to NETWORK at the top of your screen and search for other investors and investment groups in your area.

What are your minimum requirements set for an applicant to pass when screening possible tenants? 

We use it for screening   (background and credit checks) and regular rent collection, it's been great!!    

.; how to analyze properties, how to find an investor-friendly agent, how to engage in a strong due diligence process, how to screen tenants, how to manage the property, how to build a network of contractors, plumbers, electricians and other pros, how to manage the book keeping of the property, etc., etc., etc.

Some areas say you can't consider criminal history when screening applicants11.

Just make sure you do the proper screening.

Since most of them are under age 18 it doesn't concern me that much, but all adults should definitely be run through your screening.

. -- I somehow don't trust them anymore because the previous tenants they screened and found. 

I know a little of what to do from my reading, but if I got too scared (or unsuccessful) is there anyone in the area who would want to manage it as an LTR and what would you charge while following bigger pockets tenant screening, application, and  management processes?