Thorough screening and understanding of your tenants.  

Perform the same task in each app to ensure a fair comparison.Load a property with pictures and details.Market that property.See what your marketing looks like from the public's perspective.Submit a fake application to see how easy the process is.Run a credit/screening report on yourself.Enter a maintenance request, assign a vendor, and attach a fake invoice.Enter charges to the tenant's ledger.Enter recurring charges and automatic late fees.Sign documents electronically.Run owner reports.After testing a few apps, one should clearly stand out.

I needed a small 10x15 lanai re-screened.  

Quote from @Andy Ramos: It is not illegal, but it is unreasonable.The leasing fee covers all the work associated with moving the old tenant out, supervising the turnover, marketing, screening applicants, getting them under contract, moving them in, etc.

I would speak to your property manager and go over their screening process with them.

Go to BUILD YOUR TEAM at the top of the screen and look for local investors or meetups in your area.

A lot more trust is built in person vice someone behind the screen, and real estate investing is often a relationship and trust game.

This in turn led me to screening speakers (which is how I learned about notes) and even met my business partners who I started my current company I still own today.I still go to REIAs when I can (I just spoke at South Jersey REIA) and not sure anything virtual compares.

Go to BUILD YOUR TEAM at the top of the screen and look for local investors or meetups in your area.

People are spending way too much time crunching on a screen and not viewing homes in real life.