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.

You need to make sure that whatever laws are applicable in your state are included in your lease.

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.

And lenders are at end of day just statistics machines, that is the job of an underwriter, to quantify an applicant into a mathematical risk score. 

In my experience the basics for a functional RE based CRM are:Custom Fields for Data Objects (Leads, Prospects, Applications, Buildings, Units, etc...)A Screening Engine (background/credit checks, employment verification, etc)Online Rental Application (this should automatically run the application through screening)Ability to mass email/sms leads and tenants to provide informationSurveys/Inspection formsI've been building real estate CRM tools for years.

In this case their total household income (of the husband and adult son combined) does meet the requirement of being 3x the rent, but how should I apply requirements of good credit for this and other applications with multiple tenants in one application? 

@Demetrius Lindsey yes, this is still applicable today.  

Unfortunately, I have not had much success as I have barely gotten 1 application.

However, there may be alternative tax strategies out there that are more applicable to your current situation or property.

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.