They have literally millions of users and transactions to perfect their processes and features. 

If possible, I always recommend using your own capital starting out to prove process and concepts before taking hard money for flips.

Make sure you have a process in place for responding to comms efficiently and resolving issues among members and issues with the house as quickly as possible.It's worth the income and the feel-good feels knowing you're helping out your community. 

I am familiar with the rehab process, contractors, tenants, etc...

I’m relatively new to wholesaling, and I’ve been diving into the process—cold calling, direct mail, and driving for dollars.

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.

This approach allows you to present professionally and gain valuable insight into the process, which you can then replicate in-house for your next property.

They do go through a process of prequalifying you in a way but it is more property based to get it started.  

We're in the process of selling a condo that my husband inherited in Hungary.

@Jessica Heller- contact  several  lenders on the  same  day - provide them  with the  same criteria -  get  some  quotes and ask the  questions you have  ...compare the date and the feedback received and then make a  decison on  starting the pre approval process