Streamlined online rental applications

[Jim Borchardt]

I currently use a self-created rental application to screen potential tenants for rental properties I manage. Most importantly, this application and the applicant's signature give me the authorization to inquire further regarding the applicant. For example, I am authorized to call an old landlord and inquire regarding past rental history. 

I am looking for a more streamlined approach online for rental applications - however, the issue I am running into so far is no online rental application service provides authorization to inquire further regarding tenant. IE I have nothing to show an old landlord that I am authorized to inquire regarding the applicant's rental history.

Could you recommend any services online that provide a rental application or rental application builder that also provide the authorization to dig around a little more regarding the applicant?